Archive of Our Own

It's official. Katsuki has the worst luck out of any omega ever to exist.

He gasps as he climbs up onto his bed, fingers trembling where they tangle in the bedsheets.

His pussy throbs between his legs, already slick enough that his underwear slides uncomfortably across his mound at every motion. He could probably sink three fingers inside of himself easy, and ride them until he's cum atleast twice.

But that wouldn't help at all. It would just make him feel emptier inside, longing for the thick, pulsing length of an alpha cock prying him open and filling him with seed.

"Ohh, fuck." At just the thought of it, Katsuki buries his head against his pillow, which smells only of him and no alpha. It was practically an insult.

Katsuki gnaws down on the soft fluff of it, writhing so that his hips bump up against the sheets— which is better stimulation than nothing. Barely.

Not half an hour ago, Katsuki had been perfectly fine.

He'd been in the middle of patrol, about to head back to HQ to respond to a non-emergency request for heroes.

Maybe if he'd been in a rush, he would have missed the villain that had run into him headfirst. But, as it was, Katsuki had been injected with an illegal drug— a heat inducer according to the police after the arrest— and had gone down after his head got flooded with an overwhelming sense of need.

It's hardly quelled now, and Katsuki's heats already hit him hard before this. He doesn't even want to think about what'll happen if he's not able to calm himself within the next hour or two. He can just see the headlines: 'Ground Zero exposes himself as a feral omega horny for alpha cock.'

Great.

But right now, that's all he feels like. A needy, whining omega who is empty inside.

Katsuki lifts up onto his knees, wagging his ass at no one. He was the only one home, since it was the middle of the day, and he'd requested medics not to alert his number one emergency contact.

And he's starting to regret that as soon as he thinks of Deku. The alpha would be so perfect if he was there right now… face buried between his legs to get him off, licking and sucking at his cock while he fingers him with his long, thick fingers—

"Shit," Katsuki groans, unable to resist reaching down to press the pads of his fingers against himself through his clothes.

There's a squelching sound as he does, his pussy ready to be bred.

"Alphaaa…"

And so, Katsuki settles in for a long, lonely heat, unaware of the fact that the alpha of his wet dreams is already on his way.

---

Izuku rushes home as soon as he hears the rumor that Kacchan had gotten injured on the job.

It's worrying, because Kacchan would have atleast sent Izuku an angry emoji at his worried text of 'just checking in on you!', but it hadn't even been read.

And when an intern had slipped and said, "You're still here? Thought you'd be with Ground Zero!", well… of course Izuku wouldn't have stayed a moment longer. Kacchan must be in a lot of pain!

He's in such a rush that he doesn't even stop to ask what happened to Kacchan. Instead, he dashes all the way to their apartment with his quirk (which… may be a little illegal, but it's an emergency! And heroes can use their quirks in emergencies!) without taking a breath.

Which is why he's completely unprepared for the wall of enticing, addictive heatscent that wraps around him as soon as he flings the front door of their shared apartment open.

The pheromones threaten to overcome him immediately, and Izuku staggers as he trips over the genkan.

"K-Kacchan?" Izuku calls, voice hesitant.

There's a rushed shuffling sound from deeper in the apartment, and Izuku shoves his jacket from his arms, the leather tangling up at his elbows in his rush.

He huffs as he has to slow down to take it off carefully, especially mindful of the All Might pin on the lapel, which may be why he doesn't notice the pitter-patter of bare feet stumbling down the hall.

He turns, one of his arms freeing itself, ready to just shove the entire coat in a corner to get it out of the way.

He ends up with his arms full of Kacchan, instead. He's warm, wriggling from head to toe as he clings to Izuku all at once. If he had a better angle, he probably would have jumped and clawed his way up to wrap himself around Izuku's shoulders like a cat.

Izuku gets forced back a few steps, but Katsuki follows him the entire way, until Izuku ends up smooshed against the locked front door. He grunts as Katsuki presses their chests together, murmurs spilling from his throat like droplets from a waterfall.

His breathy voice whining, "Alphaaa," is something Izuku had only (guiltily) dreamed about. Usually, when Izuku and Katsuki heat- or rut-shared, Katsuki was still in control. They dealt with it early so that they wouldn't be overcome with their instincts.

But now, Katsuki is fully switched off— and a needy omega is left behind. His eyes are darkened with his lust, and shadowed by his eyelids as he tilts his head up to sniff at the air.

Katsuki butts his head beneath Izuku's, pawing at him in a way he never has before. Then he buries himself there, in that curve where he can feel Izuku nervously gulp. As his throat bobs, Katsuki's lips catch at the bump there and reflexively suckle against it.

And when Izuku moans at the pressure, Katsuki sucks harder just so that it'll leave a mark in the shape of his open lips.

Then he pulls back to moan with him, a shiver tripping down his spine until he has to wiggle his hips.

Katsuki hikes one of his legs up so that it catches on Izuku's hip, and warmth from between his thighs spills against Izuku's own groin, prompting his cock to twitch with need.

"Alpha," Katsuki demands. "Breed me."

Half of a growl builds up in Izuku's throat, catching there as he grinds out an aroused, "Kacchan," in response.

Katsuki isn't fully naked, but it doesn't matter with how desperately he ruts their clothed waists together. He just has on his tight panties (his cock peeking out from the waistband, pink with arousal) and a loose t-shirt (that Izuku belatedly realizes is his own, taken out of the dirty laundry so that Katsuki could drown himself in alpha-scent).

Izuku can feel the slick already soaked through the panties, staining his jeans with how close Katsuki is pressed.

"Okay, omega. Just breathe with me." Izuku can't move back far, but he tilts his head so that it knocks against the door, just so that the flood of Katsuki's needy scent doesn't make him lose control. Not yet, at least.

Already, he can feel himself responding to it. His alpha instincts awoke all at once as soon as he'd gotten his arms full of an omega ready to be bred full— already so needy for a cock and a knot to keep him stuffed full.

"Shit," Izuku hisses, biting his lip to pause that train of thought. "C'mere."

Katsuki mewls as Izuku lifts him, the simple act making his eyes roll back with pleasure.

"Alpha," Katsuki hums, pleased. It almost sounds lovesick as he melts into Izuku's arms, happy to lay his head against his neck— right up against his scent gland so that he can lap at it every few steps Izuku takes towards the bedroom.

When the door opens, even more of Katsuki's built up heat-scent floods the apartment. Izuku nearly tosses him from his arms in his fervid desire to take him— claim him now.

But Katsuki's nest is trashed from when he'd presumably scrambled from it when Izuku got home, and Izuku can feel his hackles raise uncomfortably in response. His omega needed a good nest, right now.

Katsuki grunts from where Izuku had deposited him, on the end of the bed that was bare of clothes, blankets, and soft things. He sits on the bare mattress cover and rolls over onto his front so that he can lift himself up onto his knees and present himself.

Izuku isn't at the right angle to see him, but he can just imagine how his underwear dip between his cheeks and how slick spills down his pretty thighs and paints them clear and shiny with his need— just begging for a tongue to come by and slurp it up.

Izuku nearly drools at the thought, and has to shake his head to focus back on the task at hand.

He climbs up onto the bed after gathering the half of the nest that had been sprawled across the floor.

He also grabs the extra pillows that Izuku had bought him last heat, that Katsuki never used. They'd be good cushion for when Izuku shoved him atop them and made him cum over and over again— didn't want his omega to get bruised knees.

Katsuki whines, high-pitched to cut through the fog in Izuku's brain. He's already teary-eyed from being partially denied of his partner's touch. But he looks so pretty, cheeks flushed pink and eyes open wide and wanting as he looks Izuku up and down.

Izuku isn't sure when it had happened, but he'd stolen Izuku's jacket right from his arm and had it bunched up beneath him, one hand fisted in the genuine leather while the other is cupping his sex and rubbing wantonly enough that they both can hear the slick sound it produces.

"Touch me?"

"Soon," Izuku promises, fingers digging so tight into a pillow that a seam pops— but doesn't rip open. He grunts as he pulls a sheet over the mound of pillows in the middle of the nest, tucking it in so that it forms a nice bottom layer.

Then he hurriedly shoves the rest of the soft things— clean towels, scented shirts stolen from Izuku's room, his hero uniform— along the outer edges to make up the round barriers.

Finally, he tugs the jacket from Katsuki's grip.

Katsuki follows after it like he's caught under a spell, crawling on his hands and knees into the very middle of the nest before Izuku drops his prize. Katsuki is back on it immediately, burying his face against the shoulders— where Izuku's uncovered scent gland had been brushing against all day every day since he'd bought the article of clothing.

His tongue slips out past his lips so that he can taste it directly, and Izuku lets him get distracted with it while he deals with himself, for a moment.

He chucks off his clothes down to his smalls, debating for a moment before also using them to line Katsuki's nest. Katsuki doesn't notice, but Izuku can see how his thighs squeeze together as even more of Izuku's fresh scent floods his senses.

They probably wouldn’t need any lube, with how ready Kacchan was… and, truthfully, Izuku was getting too worked up to wait any longer either.

Izuku slides onto the bed behind Kacchan, fitting himself between legs that part eagerly for him. Katsuki’s thighs are so soft and plush, and Izuku rubs his cheek against one as he urges Katsuki to lay his upper body flat, so that all of his weight rests on his knees. This makes his back arch perfectly, so that his privates are bared completely to his alpha’s sight.

Izuku fits his fingers beneath the plain panties, tugging them up a bit just to watch the fabric strain to hold Katsuki’s arousal. It fits between his cunt lips and makes them spread a bit, until Izuku can see how Katsuki’s clit twitches at the stimulation.

When Izuku pulls the panties all the way down, a line of slick follows. It clings to the cotton in a sticky line, until it snaps and continues its trek down Katsuki’s bare thigh.

Izuku intercepts it, opening his mouth wide so that it can envelop the soft skin. Then he suckles hard, to leave a mark there. He follows the line back up where it came from, until he can feel the literal heat pulsing from Katsuki’s pussy.

Izuku lets his breath whisper across the uncovered mound, and Katsuki shivers.

“F-fuck,” he pants, tensing when Izuku pulls his face back.

He relaxes all over again when Izuku prods his fingers up against his opening, letting him feel the width of three of them.

“Yes!” Katsuki practically shouts, angling his hips up more so that Izuku can do everything he wants. “In me— p-please put it in me, alpha.”

“Hold on, love,” Izuku murmurs. “Gotta get you stretched first.”

Katsuki begins to kick up a fuss at that, the spoiled omega that he is, but Izuku steadies him with two heavy palms on his waist. Izuku squeezes down, dragging his hands lower until he can cup both sides of his ass, and then he spanks one hand down.

It just leaves a light sting, but that much is enough to get Katsuki to fall obedient and whimpery again. Katsuki twists his head so that he can peek between his legs, and Izuku grins at him as he finally finds a comfortable spot, his lower-half lying mostly flat against the bed.

He thumbs across Katsuki's slit, carefully circling his clit. Not enough to touch where Katsuki really wants him to, but to tease. He's so wet.

Izuku can still taste remnants of his slick coating his mouth, and Izuku reflexively licks his lips as he slides those three fingers back to his hole. He nudges the longest of them against the lips, curling it a bit so that he can get it all coated before he actually delves in.

Katsuki's hips buck up, trying to ride it like a cock. Izuku has to steady him again with his free hand, gripping him against his upper thigh. He digs his fingers in so that Katsuki has more than his needy insides to think of, but all he really succeeds in doing is getting his other hand messy with slick too. Ah, well.

Izuku slides his finger inside, feeling how Katsuki's spongy insides flutter around the intrusion. The noise Katsuki makes is sinful, like drinking stolen, blood red wine.

"That feels good?" Izuku hums. "Think you can cum from just one finger?"

Izuku wiggles it in deeper, purposefully passing it across the softer part inside of him that makes him go crazy. Katsuki chokes on nothing, rocking back against it harder to get him to do it again (and then again, until he actually does cum).

"I wanna cum," Katsuki begs, untangling one of his hands from Izuku's jacket to instead reach back to try to pull Izuku's hand deeper. "Make me cum— alpha, alpha, make me cum—"

Katsuki is firmly lost in the feedback loop inside his head, then. Izuku won't tease much longer.

He slides the finger out, biting his lip as he watches the copious amounts of slick spill and follow. He coats his other fingers thoroughly in it so that he won't have to leave Katsuki empty again, and then he's prodding three of them at once to Katsuki's hole.

They slide in smooth, though it's tighter compared to just one. As he wiggles his fingers to get them in deeper, Katsuki's gasp gets caught in his chest. He's nodding his head, Izuku can see, and though half his face is covered by where he's buried it against the nest, his eyes are half-lidded and almost crossed as he gets closer and closer to release just from these few touches.

"Good boy," Izuku praises. "Cum for alpha."

Izuku curls his fingers and rocks them in and out at a steady pace. Katsuki's hips move against it too, seemingly of their own volition as the rest of Katsuki's body listlessly trembles with the motions.

With his thumb, he rubs careful circles across Katsuki's clit. The shift in angle makes Izuku's fingers press not as deep, but feel so much wider as they stretch open Katsuki's dripping entrance.

Katsuki slaps his hands down against the mattress, losing control of himself for a moment. Then he's digging his nails in so hard that they practically pop the stitches of the blanket he clung to. He rocks his hips up and down the length of Izuku's fingers, clamps his insides down, and then cums.

His cock, which had been hanging nearly forgotten above his clit, twitches valiantly as Katsuki orgasms first from his spasming cunt, then his twitching cock. It splatters its spend in short spurts against the nest, and then drips little pearls of his cum down his thighs as it hangs almost limp again.

Still, it's not enough.

"More, more alpha— oh fuck, fuck, fuck—" Katsuki's words are rushed murmurs, nearly unintelligible as he doesn't slow his humping for a second. Even as his cunt trembles around Izuku's fingers, he squeezes his thighs shut to try to keep him there.

But without thrusting or any sort of stimulation beyond the little in-and-out movements Izuku can do with the tips of his fingers like that, Katsuki would surely go insane with need. He needed more than that (like… a knot) if he was going to calm down.

"Calm down," Izuku shushes him. "I'll help you, Kacchan, I promise."

Katsuki doesn't still one bit. Not even when Izuku growls at him, trying to prompt his omega to listen to his alpha.

And, well. If it was only his pussy that he was going to pay attention to…

Izuku pries Katsuki's legs open. It's easy when they're shaky and weak after his orgasm. Katsuki inhales sharply in surprise, and then makes an indignant hiss when Izuku proceeds to flip him onto his back.

His wet fingers slide across Katsuki's inner thigh, briefly, and then those same three fingers press soundly against his clit.

Katsuki is nodding his head all over again from that simple touch, but he was still jerking his hips against Izuku as if he was his favorite sex toy, eager to get off as much as possible as fast as possible.

Izuku lifts his fingers and then brings them down sharply against Katsuki's unprotected slit. It makes a wet noise, almost higher in pitch than a normal slap would sound, but that entirely gets overshadowed by the shocked wail Katsuki produces.

"Alpha!" He cries out, his hands scrambling at the air before they find purchase in his own hair, tugging at his scalp as he lifts his head to watch.

Izuku spanks his cunt again, and Katsuki's back arches. Izuku keeps his hips pinned with his other hand, casually noting the way Katsuki's hole (fucked partially gaped after Izuku's big fingers pried it open) clenches on nothing.

So Izuku does it again, and then again— until that flushed, sensitive skin is even more red and swollen from the abuse.

And then Izuku advances to using his full palm. Katsuki's slick has almost thoroughly coated him down to the wrist, and it splatters messily with each impact that cuts between them.

Still, the harsh tension tugging each of Katsuki's muscles taut slowly begins to loosen. His legs go limp, one going straight and the other curling around Izuku's back.

The humiliation of having his pussy spanked (the hole normally meant only for pleasure being attacked with punishing, humbling pain) makes him go obedient and mewling once more.

"Deku," Katsuki pants when Izuku lets his final spank land softer than the rest, leaving his fingers back where they started— up against Katsuki's swollen clit.

His cock has fallen to one side, and Izuku tries so hard not to think of it as cute because Katsuki would kill him if he accidentally said it aloud— but it's pretty as Izuku's breath ghosts across the wet skin. Pink from tip to base, until it grows red where Izuku had let his cunt spanking reach high enough to lay across his mound as well.

Izuku kisses it, and Katsuki gasps. Izuku's tongue drops past his lips as he works on cleaning up the excess that it had spilled across Katsuki's belly, but he gets distracted with bathing it in his own spit instead.

Katsuki's cock strains as Izuku holds it steady with his fingertips, and Izuku can feel how Katsuki's eyes bore into the sight.

Both of Katsuki's legs come to rest on his shoulders, then.

Katsuki bears down when Izuku takes the head past his lips and suckles on it, gentle and loving compared to the spanking he had just received.

Izuku hopes to keep him calm like that, trying to ease his body up towards its next orgasm so that he doesn't get overstimulated all at once.

He laps at the stringy lines of cum that slides down the base of Katsuki's dick, pulling off with a groan to swallow down what he's already got in his mouth. Then he goes right back, trailing lower to catch where his milky cum had almost dripped between his own cunt lips.

Izuku leaves a kiss atop his clit just because he can, and then goes back up to his treat.

He catches eyes with Katsuki as he does, red-rimmed and bleary from his needy, overwhelmed tears.

"Please fuck me," Katsuki begs, miserably. The 'please' is out of character, but the way his eyebrows are furrowed and his sullen pout is all Kacchan.

"I've got you, baby," Izuku promises. He cups the full length of Katsuki's dick against his palm and kisses the head one last time, his tongue briefly tracing along the indent where his cockhead met the shaft. Maybe he'll be able to give it more love later.

Then, Izuku is climbing up Katsuki's body to give him the rest of the attention that he wants.

His cock ruts against Katsuki's folds, their arousal mixing almost immediately. Katsuki's hips lift up purposefully so that he can rub against almost the full length of it.

Katsuki lifts himself onto his elbows for more purchase, and Izuku is quick to hold Katsuki's hips down so that he doesn't accidentally sink inside too soon.

"Please!" Katsuki practically shouts, his jaw tense as he clenches his teeth. "F-fuck me, alpha— give me your knot!"

Izuku pulls back a few inches and that makes Katsuki go wild. He writhes in Izuku's grip, and there's a brief scuffle as Izuku has to grip him tight, hands firm on either of his hips, so that he doesn't get enough of an angle to actually take Izuku's cock down to the knot.

Katsuki's arms shake as he valiantly tries to hold up his own weight— but the heat and the orgasm has exhausted him. He drops a few seconds later with a feral, frustrated sigh.

Izuku lets go with one hand, and Katsuki begins to move around again.

"Wait— hold on, love." Izuku shushes him as Katsuki sobs, legs kicking out to try and wrap around Izuku's waist and yank him inside his prepped hole.

Izuku strains to reach the nightstand, slapping around the surface for the box of condoms that they more often than not leave out.

When he doesn't find it there, he drops lower for the drawers. As he shoves his hand around— cringing as he messes up the careful organization that Katsuki insisted the nightstand have— Katsuki busies himself by sinking his teeth into the tender flesh of Izuku's chest and suckling, as if to punish him for making him wait longer.

Izuku groans at the pinch, but reaches his other hand up to cup against the back of Katsuki's head so that he won't pull away and try to do anything else. He encourages him with a rumble from deep in his chest, and Katsuki goes limp as those vibrations go right through his open mouth to empty his pretty little head.

He laps at Izuku's bare skin without removing the suction of his lips, almost low enough that he could take the nipple in his mouth. Izuku lets his hand drop, and Katsuki doesn't let go.

"Okay," Izuku breathes, trying to keep himself level-headed. His cock was throbbing between his legs, hanging low and heavy as it spills precum against Katsuki's belly with the position that he's put them in.

It's hard to stay calm, though, because he can't find any fucking condoms. Not even an empty box to signify that— yes, today is the day that they finally ran out of their bulk buy of condoms. Katsuki must have thrown it away that morning.

Katsuki's body rolls as Izuku shifts, accidentally tucking his knee right up between Katsuki's open thighs. He clamps around the thick of it, his cunt rutting against it readily. Izuku can feel how his clit, swollen with need similar to how Izuku's cock is, slides wetly across his skin.

Izuku lets him, because no way was his cock going inside now. That pussy of his would just have to deal with fingers and a tongue this round, apparently.

Izuku had a bad habit of getting quickly overcome when he sinks inside of Katsuki's body, feeling how that slick, warm hole opens up to suckle him down greedily and urge each wave of cum from his balls as much as it can— even with the condom in the way.

And if Izuku cums inside of him now, with Katsuki in the middle of his heat— the most fertile his body could be at any given moment— well…

Izuku tries not to think of it, because that just makes him harder.

Izuku shifts back, taking away Katsuki's new toy. Just those few moments of him grinding against it has left Izuku's leg soaked, and a line of slick connects them until he goes back too far and it snaps, leaving Katsuki's cunt looking lonely, wet, and empty.

Izuku flops onto his stomach, shoving his full palms beneath Katsuki's ass to drag him down the bed. He grinds his cock against the bed, rough as he grinds once— twice to get the edge off.

Then he buries his face against those plush, swollen folds. The perfect distraction from the dilemma at hand.

"Noooo," Katsuki starts to whine, and then interrupts himself with a purr of, "Fuck! Yes— Right there!"

Izuku's tongue slips inside, swirling around to clear the excessive amounts of slick that had been fingered out of him earlier. It tastes so good, and Izuku squeezes his eyes shut as he drinks it down.

And then, once Katsuki is all clean, Izuku focuses on fucking him with his tongue. It, of course, can't go nearly as deep as his cock (or even his fingers), but it wriggles and presses against those sensitive spots against Katsuki's inner walls. Izuku knows exactly where to touch to drive him crazy, to bring him to the edge in a way that he, himself, can't even do.

Katsuki's fingers shake as they tangle in Izuku's hair. He doesn't shove his alpha's face in deeper or try to pull him back, he just trembles as he lets the sensation wash over him.

His gasping moans and his taste set alight Izuku's senses, and he could honestly die happy between his omega's legs.

But even if it's skilled, his tongue isn't enough to abate the building heat in Katsuki's veins. Katsuki's thighs clamp against his ears as he rides Izuku's face, to the point that Izuku can't even get enough room to finger him for extra stimulation.

Instead, he has to wriggle higher so that he can focus on Katsuki's clit for a moment.

Katsuki is begging for more above his head, the words muffled with how he's trapped against Katsuki's pussy, but Izuku gets distracted by the heady flavor coating his tongue and the deluge of heat-scent directly against his nose.

He wants to cum, just about as badly as he wants to sink his throbbing cock deep in Katsuki's cunt and empty his balls there, 'til Katsuki couldn't move without it spilling out.

Katsuki's legs tremble as Izuku sucks hard on his clit, partially to ground himself but mostly because Katsuki is drowning him with how tightly he's holding on. When they drop flat to Izuku's shoulders again, exhausted, Izuku pulls back with a gasp and fills his lungs with blissful air.

Then he dips down again, ready to urge Katsuki towards his orgasm to try to fruitlessly quell his poor omega's needy heat.

Katsuki stops him, bending himself in half to press his palms to Izuku's cheeks, slick as they are with his own arousal. And, as soon as Izuku blinks his eyes open, his pouty lips are dropped open with half of a whorish moan and half of a distressed whine.

Izuku brings a hesitant hand up to circle his fingers around Katsuki's wrist, but he starts to rub little circles against Katsuki's clit instead, distractedly as Katsuki starts to beg for him.

"Please," Katsuki starts. His voice is hoarse from all of his moaning. It's like warmed sugar, but twice as sinful. "Please fuck me, Deku."

When Izuku doesn't immediately shush him, Katsuki twists impatiently and wiggles himself even closer to Izuku, as if his pussy wasn't currently nudged right up against Izuku's chin.

"Alpha, I need it. Fuckin'— need your cock splitting me open, j-just the tip. Just a little bit— please—"

Izuku is only so strong.

"J-just the tip," Izuku confirms, shaky. He sits up on his knees, biting his lip as his cock swings up and smacks against his lower belly. Shit, he's never been so hard.

He jerks himself off briefly, but Katsuki reaches down to lift his legs up and lock his fingers beneath the knee— so that all of him is bared to Izuku's view.

"Fuck me, fuck me, fuck meeee," Katsuki is murmuring beneath his breath in a mantra. It cuts off immediately when Izuku carefully nudges his cock against his pussy just like he wants.

His eyes roll as Izuku slowly sinks in, his fist forming a tight barrier to stop himself from going in further than just an inch below the tip.

Katsuki is trying to urge him in deeper, their prior agreement all but forgotten as he gets part of what he's been yearning for all this time. He uses his own grip on himself to rock up against it, nudging Izuku's knuckles nearly out of place.

Izuku squeezes down almost painfully as he lets Katsuki fuck himself on his cock, hyperfocusing on the sweat that's beading up and dripping off of his own neck. If he focuses on anything else, he will lose control.

And Katsuki knows this.

"Alpha," his naughty omega croons. "Deku… I want it so bad. You're so f-fuckin' big… even just the tip is splitting me open like this, alpha. See?"

Katsuki moans, and then cuts himself off. And that is enough to make Izuku slip, his eyes cracking open.

He's greeted to the sight of Katsuki slipping his fingers between them, parting his cunt lips so that Izuku can see just how wide open his cock is splitting him. Just the tip, and Katsuki's pussy is straining, but so fucking eager for more.

"Fuck," Izuku groans at the ceiling. His hips jerk forward, reflexively, and the tight hold of his fist matters little with how slippery it's gotten. His cock slips inside just a few inches more.

Katsuki nods his head endlessly, watching as his cunt is fed with alpha cock. He loses his voice the deeper Izuku goes, and his eyes squeeze shut tight when Izuku has to force his hips to still.

Over half of his cock is snugly trapped inside. His thumb knuckle bumps against Katsuki's sensitive clit, and it makes the latter shiver having it played with while he's getting stuffed.

"A-alpha…" Katsuki wheezes, though the words are dreamy and content. "I'm so full…"

Izuku breathes a sigh of relief, looking away as he gathers the shattered remains of his control back, piece by piece.

Going in deeper than he meant to wasn't the end of the world… he just needed to stay focused— let Kacchan take what he needs so his heat will pass.

Then Izuku will lock himself in the bathroom with a scented shirt from the nest and jerk off until he can't cum anymore (and try to ignore the way his instincts are furiously fighting with him to breed the willing, fertile omega nestled beneath him). That's the plan.

Except, Katsuki is getting more worked up now that Izuku has stilled.

His insides begin to pulsate around his cock, different than before when he was just trying to entice him deeper.

Katsuki's mouth drops open again as he focuses on the feeling, and Izuku digs his fingers too tight into Katsuki's pretty skin as Katsuki clamps down tight and jerks his hips up. It makes Izuku's cock thrust into him shallowly, just barely so that he can feel the swelled curve of the very tip nudge against his g-spot.

That's all he needs, apparently.

Katsuki goes tense all at once, his breath catching in his throat. His toes curl, his body jerks, and then—

His pussy throbs one last time and an influx of heat between them prompts Izuku to look down to where they're joined. He's greeted to a deluge of slick and arousal and— and cum soaking his cock.

His omega's hole, red and twitching and stretched wide, doesn't stop those rhythmic pulses until the flow stops— and Katsuki goes limp and boneless in the nest. The only reason his legs don't flop out is from that death grip he has on the backs of his own thighs.

He… came.

Katsuki orgasmed with only half of Izuku's cock inside of him, his warm cum practically squirting around the width of him.

Holy shit.

Izuku's hands drop, falling to where Katsuki's own still rest beneath his knees as he keeps himself held open for Izuku.

Izuku presses down hard, bending him so that his knees nearly press to the mattress.

Then he pistons his hips forward, shoving inside the rest of his cock. Katsuki's soft, still trembling cunt, opens up obediently and quivers around the full length of Izuku's cock when he pauses. Just to make sure he won't cum with the first stroke.

Katsuki, meanwhile, has arched his back as best he can with the position and the pinning. His eyes have rolled to the back of his head, lower lip caught between his teeth as he bites down on it to try not to lose his head completely to the pleasure (atleast, before he's gotten fucked atleast a bit). Little tears soak his eyelashes, partly from his begging but mostly because it feels so good.

Katsuki's chest shudders when he suddenly inhales, as if he forgot to breathe.

Then he blinks, his eyes gaining focus for just a brief moment. They focus on Izuku's, and a dopey grin grows on his face.

"Hnngh… th-thank you, alpha," he gasps.

Izuku growls as he jerks his hips back only to fuck in hard, letting their skin slap together noisily as he starts to fuck Katsuki the way he's wanted this entire time. A reward, for him being such a lewd omega.

Katsuki lets out a curse that gets lost as he moans and grunts when Izuku keeps that pace up, driving Katsuki's hips down into the mattress with the force of his thrusts until they bounce back up and meet him halfway.

"You're so perfect, Kacchan," Izuku moans, "So good for me. Taking my cock all the way down to the base. Good omega, take it— take it…!"

"Deku!" Katsuki cries out as Izuku's pace picks up. He frees his fingers from where they'd been caught beneath Izuku's, and he reaches up to tug Izuku down.

As soon as he's able, his arms wrap around Izuku's shoulders and he buries his face against Izuku's own weeping scent gland. Izuku reaches deeper with this new position, somehow, his cock angled enough that it knocks right against that super sensitive spot inside of his omega.

Katsuki hides his face against the curve of Izuku's shoulder, and Izuku growls when that just makes Katsuki bare his neck to his greedy gaze.

Izuku watches as Katsuki's throat bobs as he fails to swallow down his moans, unable to focus on anything except the swelling knot at the base of Izuku's cock— which kisses against his rim with each downward thrust that he's pulled into.

His cock has gotten trapped between them, and Izuku can feel how that barely flagged erection gets hard all over again when he starts to drown in the pleasure. Izuku kind of wants to watch him cum all over himself again, but if he stops thrusting now just to tease again, they both might go crazy.

So he keeps up that pace, unaware of the harsh grunts he sounds as he focuses on fucking Katsuki through his next orgasm. And— his own.

He wanted to fill Katsuki up with his cum until it had nowhere else to go but spurting around his inflated knot. Wanted to fill up Katsuki's little tummy and feel how it warms up from the inside out with the seed he was keeping safe— maybe long enough for it to catch.

Shit, he wanted to breed his omega so bad. Izuku hikes Katsuki's hips up higher, letting Katsuki's legs hook against his elbows so that he has more room to press their faces together.

The hurried kiss he gives him is messy and mostly his lips missing Katsuki's (because he doesn't slow down in the slightest), but Katsuki was kind of addicted to kisses. He chirps between each one, the noise of pure omega-happiness, and he returns them with a smooch or two of his own.

Izuku's pace stutters as his knot begins to catch, growing wide enough that he has to physically tug and shove it in and out. Katsuki loves it by the way his moans kick up in octave.

Katsuki's legs wrap around his waist, slowing Izuku's thrusts by about half speed— but it just brings him in harder, rougher. Traps him inside.

"Gonna kn-knot," Izuku tries to warn, sitting up to atleast try to pull out and not fuck his omega pregnant.

Katsuki grinds his hips in little circles, until Izuku is moaning in tandem with him.

"Knot me," Katsuki agrees eagerly. "Cum in me, make me full."

And, just like before, Izuku is only so strong.

He thrusts in deep one last time, egged on by Katsuki's greedy sounds, and stills. His knot balloons out to its widest point, locking them together.

As soon as Katsuki feels the heat of the cum filling him up, he drops limp. As if everything in him suddenly clicked into place.

Izuku trembles as he grabs onto Katsuki's hips, pressing into his ass as close as physically possible so that his omega won't spill a single drop.

He moans from deep in his chest as his cock pulses inside of Katsuki's warm pussy,  as he climaxes the hardest he ever has. Izuku almost blacks out from the rush of endorphins, especially when Katsuki's pleased-omega scent hits him at the same time.

Izuku throws his head back as he keeps cumming, coaxed onwards as Katsuki's insides practically milk him for his spend.

"So full," Katsuki moans from where he's practically melted into the mattress, soft and still and pliant.

Izuku blinks his bleary eyes open, only to spot the bulge in Katsuki's tummy. Where his cum had filled up his omega so well that it almost ran out of room inside of him.

Izuku growls as he thrusts his hips. His knot doesn't let him go far, but it's enough that Katsuki can feel how his insides get knocked against.

His vision hazes out again as he watches Katsuki's body jump with the renewed pace, watches as that bump grows large and large as Izuku. keeps. cumming. Fuck!

"Omega," Izuku rumbles, "My omega— my good little Kacchan. Look how perfectly you take your alpha."

Katsuki's fingers paw at his stomach, briefly hiding it from view. As soon as he feels where he's been overstuffed, and feels how Izuku's cock continues to nudge up against him from the inside, he curls up and cums again.

His poor cock, already fucked to the point where it couldn't even get hard anymore, simply just twitches against his bloated tummy as he cums dry.

Izuku isn't sure if he's ever seen Kacchan cum so many times at once, but he urges him through it with little nudges against his oversensitive clit.

With a huff, Izuku plants his other hand on the bed and watches as Katsuki comes down from that sudden high. His cock is spilling its last spurts of cum, and Katsuki is so overfilled that it immediately splurts out around the tight seal that his cunt has created around the girth of his knot.

The sensation makes Izuku moan weakly, and he has to drop his weight fully onto his forearm so that he doesn't crush Katsuki beneath him.

Katsuki is on him immediately, murmuring breathless nothings as he wraps his arms around Izuku's shoulders and hides himself back up against his scent gland. "So full… so good," he hums.

Izuku, almost delirious with the pleasure, can only hum back and bump his head against Katsuki's cheek, nuzzling their faces together.

---

Izuku swipes a warm towel across Katsuki's back, wiping away the sweat and cum that had somehow found its way up that far. Katsuki is sitting criss-crossed, glaring at the wall, and his skin is still blushing with the after-effects of their… session.

Once he's a bit more dry, Izuku lets the towel fall to cover the copious wet spot that they had created in the very middle of the nest.

Then he sits back on his haunches so that Katsuki has enough room to stretch and lounge out, until he's ready for the next round.

As soon as he's made himself comfortable, Katsuki flops onto his back and wiggles a few inches closer, just so that they touch.

"Stupid shitty Deku, cumming inside me so much," Kacchan grumbles beneath his breath the entire time.

His voice is hoarse and it makes Izuku's instincts preen, to know that he satisfied his omega that much.

Katsuki's belly is still a bit full, and Izuku will probably have to finger him open to help him let out all that cum trapped inside.

Katsuki has scooted close enough that Izuku only has to bend down a few inches to press their faces together.

"Sorry, Kacchan." Izuku lays a gentle kiss against his cheek, really only half sorry.

Katsuki turns his nose up at Izuku, but Izuku can still see the pleased grin parting his lips.

"… My heat isn't over yet."

He says it in a way that might be casual if not for the way he looks Izuku directly in the eye as he twists onto one hip and reaches back to grip one side of his ass. He parts the cheeks to show the cum still slowly oozing out of his fucked-open hole. Izuku has a perfect view of it all, how it spills over Katsuki's ass and soaks into the nest.

Izuku gulps, but his cock is already eager just from the sight. It's hardening the longer Izuku looks. He hadn't expected Katsuki to be ready now, but…

"Wonder how much more you can breed me," Katsuki continues, resting his head against his upturned palm. "If you can even cum anymore, shitty alpha."

Izuku huffs, but he can't find it in him to be mad when Katsuki spreads his legs further to make room for him. And especially not when Katsuki pulls Izuku in and grinds himself down against the length of his cock once more, to entice him back inside.

"You're insatiable," Izuku laughs, but gathers Katsuki in his arms and readies himself for another round or two (or three) until Katsuki's sudden heat is over and done with, and his omega is satisfied.

"Breed me more, alpha," Katsuki commands, voice outlined with a pleased purr. Izuku kisses him so that he can feel the hint of vibration from it directly against his lips.

They still didn't have any contraceptives but… what's done was already done. No harm in filling him more, right?

Besides, Izuku was also kind of eager just to see how much more cum Katsuki could take, anyway.