Izuku’s mouth is still working weakly at Katsuki’s thumb, the taste of him thick and salty on his tongue, but his mind is somewhere else entirely. It’s back in the bath, pinned against the tub’s edge. It’s on the promise Katsuki had growled into his skin. His body feels hollowed out, used, and yet it’s screaming for the one thing it hasn’t had. That big cock in his pussy. The final lesson.

He pulls off Katsuki’s thumb with a soft, wet sound. His green eyes, glazed and submissive just a second ago, sharpen with a desperate kind of focus. He doesn’t ask. He moves.

Scrambling back on the giant bed, his small body a pale smudge against the dark silk, he arranges himself right in the center of Katsuki’s view. He hooks his hands behind his knees, pulling his legs up and apart. Then, with a trembling effort that makes the muscles in his slender thighs quiver, he crosses his ankles behind his own head. The position is obscene, vulnerable, an offering. He uses his free hands to spread himself open, his fingers pulling at his own slick, swollen flesh.

“Kacchan,” he breathes, the hero name a prayer. “Please. No more teasing.”

Katsuki hasn’t moved from where he stood at the bedside. His red eyes are locked on the display, tracing the lines of Izuku’s stretched body, the glistening proof of his arousal. A slow, predatory smirk pulls at his mouth.

“Look at you,” Katsuki says, his voice a low rumble. “My devoted little fan. What do you want?”

“I need it,” Izuku whines, his hips giving a helpless little jerk. His fingers tremble as he tries to hold himself wider. “I need your… your big hero cock. Please, Kacchan. Ruin my tiny kitty. Fuck it open. I can’t wait anymore, I’ll be good, I promise, just—”

“You’ll be good?” Katsuki repeats, finally stepping closer. The bed dips under his weight. He doesn’t touch yet. He just looks, his gaze a physical heat on Izuku’s exposed core. “You’ll do anything?”

“Anything!” Izuku gasps, nodding frantically, his curls bouncing. “Anything you want. I’ll do anything, just please, please fuck me.”

Katsuki leans over him, one hand braced on the mattress beside Izuku’s head. He’s so big, blotting out the city lights. “Anything,” he murmurs, as if considering. “You’d even be my little boy slut? My secret boy wife? Let me fuck you whenever I please? Breed this tight little cunt full of my kid?”

The words are filthy, impossible, a contract written in dirt. Izuku’s brain stutters. Boy wife. Breed. A kid. His mother’s scared, sheltering face flashes behind his eyes for a split second, then is burned away by the sheer, desperate need coiling in his gut. His pussy clenches around nothing, aching.

“Yes,” Izuku sobs, his composure shattering. He’s crying again, but it’s not from fear this time. It’s from want. “Yes, Kacchan, yes! I’ll be that. I’ll be anything. Just claim me. Please.”

Katsuki’s smirk widens into a full, wicked grin. “Good boy.”

Katsuki’s grin doesn’t fade. He shifts his weight, his hand leaving the mattress to wrap around the base of his cock. It’s fully hard again, thick and heavy in his grip, the head glistening. He brings it down, not to enter, but to rub. The broad, hot crown drags through Izuku’s soaked folds, over his swollen clit, and back down to his desperate, fluttering hole.

“You want it here, fanboy?” Katsuki growls, pressing just the tip against him, not pushing in. “This hungry little slut.”

“Yes! Kacchan, please—”

“Begging’s done.”

In one brutal, piston-driven thrust, he slams his full length home.

Izuku’s world whites out. The stretch is immense, a burning, splitting fullness that steals the air from his lungs. He feels every inch, every ridge, as it drives deep, deeper than he thought possible, until their hips are flush and something inside him yields with a sharp, internal pop. Katsuki’s cock is buried to the hilt, his heavy balls pressed tight against Izuku’s ass.

“Fuck,” Katsuki groans, the word punched out of him. His head drops, ash-blonde spikes brushing Izuku’s forehead. “Look at that.”

Izuku’s tear-blurred gaze drops to his own stomach. There, just below his navel, is a distinct, obscene bulge. The outline of Katsuki’s cockhead distends his pale, freckled skin. A choked sound escapes him. He lifts a trembling hand and presses his fingertips against the swell.

Inside him, Katsuki jerks with a ragged groan. “Feel that? That’s me in your womb, boy. You took all of it.”

Izuku rubs the bulge, fascinated, horrified, utterly claimed. The pressure is immense, a deep, internal ache that is already shifting, melting into a shocking, radiant heat. His pussy clenches instinctively around the invasion, and he feels Katsuki’s cock twitch in response.

“Move,” Izuku whispers, his voice wrecked. “Please, move.”

Katsuki doesn’t pull out. He grinds. A slow, deep rotation of his hips that rubs his entire length against every screaming nerve inside Izuku. The sensation is unbearable. Izuku’s back arches off the bed, a broken cry tearing from his throat.

“Tightest fucking thing I’ve ever had,” Katsuki rasps, his breath hot on Izuku’s face. He’s watching every reaction, his red eyes blazing. “Sucking me in. Your little cervix is kissing the tip, you feel that?”

Izuku can feel it—a deep, internal pull, a frantic fluttering right where the unbearable fullness is centered. He nods, gasping. “Feels… so big. So deep.”

“It’s where you belong. My secret boy wife. Gonna keep you full of me.” Katsuki finally draws back, a slow, slick slide that makes Izuku whimper at the loss, before driving in again, hard and precise. “Tell me how it feels.”

“Good,” Izuku sobs, his hands scrabbling at Katsuki’s scarred shoulders. “So good, Kacchan. Your hero cock… it’s filling me up. It’s perfect.”

Katsuki sets a punishing rhythm, each thrust bottoming out with a wet slap of skin. The bedframe creaks in protest. “Gonna ruin you for anything else. This pussy’s mine. Say it.”

“Yours!” Izuku cries out, his legs trembling where they’re hooked behind his head. “Only yours, Kacchan, please—”

“Gonna breed this pretty cunt so deep you’ll feel it for days.” Katsuki’s pace is relentless, his control absolute, every movement designed to hit that devastating, internal spot. Izuku can feel his own climax coiling again, a tight, electric spring in his gut. His vision is swimming, his cries turning into mindless, rhythmic pleas with every drive of Katsuki’s hips.

Katsuki’s rhythm doesn’t falter; it deepens. Each thrust becomes a targeted, brutal assault, the thick crown of his cock hammering against that deep, fluttering barrier inside Izuku with a wet, meaty sound. “Right there,” Katsuki grunts, his voice stripped raw. “That’s your womb, boy. You feel me knocking?”

Izuku can’t speak. He can only gasp, his body bowing on the bed, his crossed ankles straining behind his head. The sensation is too much—a sharp, bright pressure that borders on pain with every impact, yet each one sends a shockwave of molten pleasure radiating through his core. His fingers dig into Katsuki’s biceps, feeling the corded muscle work as he pistons into him.

“Answer me,” Katsuki demands, slamming home particularly hard. Izuku’s vision sparks.

“Y-yes!” Izuku chokes out. “I feel it, Kacchan, you’re—you’re so deep—”

“Gonna fuck a baby right through that cervix,” Katsuki snarls, his composure cracking into something feral. His pace turns punishing, the bedframe slamming against the wall with every drive. “Gonna stuff you so full of my cum you’ll taste it for a week. You want that?”

Izuku’s climax hits him like a seizure. It rips through the overstimulation, a white-hot wire of pure sensation that snaps taut from his clit to the deepest part of him Katsuki is brutalizing. His back arches violently off the silk, a silent scream on his lips before sound finally tears free—a high, shattered wail.

His cunt convulses, a series of frantic, milking clenches around the massive intrusion, and then he’s squirting, a hot gush of release that soaks Katsuki’s lower abdomen and the sheets beneath them with a sound like a splash. The scent of it, musky and sweet, fills the air between their panting mouths.

Katsuki groans, a deep, animal sound of satisfaction. “Fuck, that’s it. Squirt all over your hero, you perfect little slut. Your cunt’s hugging me like it never wants to let go.”

He doesn’t stop. Not for a second. The ruthless pounding continues, even as Izuku shudders and sobs through the aftershocks, his sensitive, spasming walls overwhelmed by the relentless stretch and friction. The overstimulation is agony. It’s ecstasy. Izuku feels raw, split open, owned in a way that transcends his understanding.

“Please,” Izuku whimpers, tears streaming into his hairline. “It’s too much, I can’t—after cumming, it’s too—”

“You can,” Katsuki interrupts, his breath hot and ragged. He leans down, capturing Izuku’s mouth in a biting, possessive kiss. When he pulls back, his red eyes are wild. “You will. You take what I give you. Your body’s mine to use. Now cum again.”

He shifts his angle, hiking Izuku’s hips higher, and redoubles his efforts. The thrusts are shorter, harder, a brutal jackhammering focused purely on that tender, battered spot deep inside. The wet slap of skin is obscenely loud in the sterile room.

Izuku’s cries turn into a continuous, broken stream of yes and Kacchan and yours, his mind dissolving into a haze of sensation and submission. He can feel another climax, impossible and inevitable, already coiling in the wreckage of the last one, built on a foundation of pure, brutal claiming.

The second climax hits Izuku like a freight train, a convulsive, full-body seizure that rips a raw scream from his throat. He squirts violently, a hot, drenching flood that soaks Katsuki’s stomach and pools beneath them, his cunt clamping down in a series of frantic, milking spasms around the thick cock splitting him open.

“That’s it,” Katsuki snarls, his control shattering. “Squeeze it out of me, you greedy little bitch.”

His hips piston faster, harder, the jackhammer rhythm turning brutal and erratic. The wet slap of skin is deafening. Izuku can only sob, his vision whiting out as the overstimulation burns through the pleasure, a feedback loop of agony and ecstasy that holds him suspended.

Katsuki’s breath hitches. A guttural, broken sound tears from his chest. “Taking my seed—right fucking now—”

He slams home one final, devastating time and goes rigid. Izuku feels it—a deep, internal pulse, then a scalding flood as Katsuki’s cock jerks inside him. The heat is shocking, a liquid rush that fills him impossibly fuller, a sensation of being packed, claimed, seeded at his very core. Katsuki groans, long and low, his body shuddering as he empties himself in thick, pumping spurts.

“Feel that?” Katsuki pants against his neck, his voice wrecked. “That’s my cum. Flooding your womb. Breeding you deep.”

Izuku does feel it. The hot, spreading weight. The subtle, continuous twitch of Katsuki’s cock as it delivers more. He feels stuffed, marked, irrevocably changed. A weak, overwhelmed noise escapes him.

Katsuki doesn’t pull out. He grinds his hips in a slow, possessive circle, working his spend deeper. “Gonna take every drop. You promised.”

“I… I am,” Izuku whimpers, his body trembling with exhaustion and residual shock. The fullness is a constant, profound pressure. “It’s so hot, Kacchan. So much.”

“Not enough.” Katsuki’s voice is already regaining its edge, the predatory focus returning. He shifts, his softening cock still buried to the hilt, and rolls them onto their sides without breaking the connection. Izuku is pulled against his chest, a doll in his arms. “We’re not done. You think one load is enough to claim this?” He palms Izuku’s lower belly, pressing down. Izuku gasps, feeling the internal shift.

“But… you came,” Izuku says, dazed. His legs, still hooked awkwardly, begin to ache.

“And I’ll come again. And again.” Katsuki nips at his shoulder. “Until this cunt is so full of me you leak for days. Until the thought of anything else inside you makes you sick. That’s what ‘boy wife’ means. Now uncross your legs. We’re changing positions.”

Izuku obeys, his limbs leaden as he lets his ankles slide from behind his head. The movement makes Katsuki’s cock shift inside him, and a fresh trickle of warm cum leaks out around the girth. Katsuki tsks.

“None of that.” He manhandles Izuku onto his stomach, hiking his hips up. The sudden angle drives him deeper. “You keep it in. Every drop is mine.”

Izuku buries his face in the silk sheets, smelling sex and sweat and his hero. He feels Katsuki’s hands on his hips, large and branding. Feels him begin to move again, a slow, deliberate rock. He’s still hard. Izuku’s spent, oversensitive cunt clenches weakly around the renewed intrusion.

“Kacchan…”

“What?” The thrusts gain strength, the wet slide easier now, lubricated by his own release.

“It’s… a lot.”

“It’s what you begged for.” Katsuki’s pace builds, the familiar, punishing rhythm re-establishing itself. “You said ‘anything.’ You said ‘ruin me.’ So take your ruin, Izuku. Take it and thank me.”

Katsuki’s rhythm turns feral, a brutal, jackhammering pace that drives the breath from Izuku’s lungs with every slam. The wet, meaty slap of their bodies is obscenely loud, a percussive beat to Izuku’s choked sobs.

“Talk,” Katsuki snarls, his hands vise-tight on Izuku’s hips. “Tell me what this is.”

“It’s—it’s you fucking me,” Izuku gasps, his face grinding into the soaked silk. “Fucking my… my cunt.”

“My cunt,” Katsuki corrects, punctuating the words with a devastating thrust. “Say it.”

“Your cunt! Kacchan, your cunt, you’re ruining it—”

“Ruining it?” Katsuki leans over him, his sweat dripping onto Izuku’s back. “Look at you. You’re fucking milking me. This greedy little hole is sucking me deeper. You love it.”

Izuku does. The overstimulation is a white-hot brand, but beneath the raw ache is a deep, throbbing fullness that feels like truth. His body clenches instinctively, trying to pull Katsuki deeper still. “I love it,” he whimpers, the confession torn from him. “I love your cock in my cunt. Please, don’t stop.”

“Wasn’t planning on it.” Katsuki’s voice is a guttural rasp. He shifts, pulling Izuku up onto his knees without ever slipping out, the angle change making Izuku cry out. “Gonna fuck a baby so deep into you, your stomach swells with it. Gonna see my cum leaking out of you for days. You want that? Want my kid in you?”

The filthy promise coils in Izuku’s gut, a heat separate from the friction. “Yes,” he sobs, his arms giving out, his upper body collapsing back to the bed. “Put a baby in me, Kacchan, please, breed your boy wife—”

Katsuki’s control snaps. He mounts Izuku fully, his chest a heavy, sweaty weight on Izuku’s back, his pace abandoning all rhythm for pure, animalistic pounding. The bedframe screams in protest, slamming into the wall with a sound like gunshots.

Izuku’s third climax takes him by the throat. It isn’t a wave; it’s a detonation. His vision tunnels, his mouth opens in a silent scream, and then he’s squirting, a hot, violent gush that soaks his thighs and the already drenched sheets beneath them, adding to the massive, cooling puddle. His cunt spasms, a frantic, fluttering pulse around the massive cock splitting him open.

“That’s it,” Katsuki grunts, his thrusts turning ragged, desperate. “Squeeze it out of me. Milk my fucking seed.”

Izuku can only shudder, his body convulsing through the endless release, the pleasure so intense it borders on pain. He feels Katsuki swell inside him, the thick vein on his cock pulsing against Izuku’s sensitive walls.

“Taking it—” Katsuki snarls, his teeth sinking into the juncture of Izuku’s neck and shoulder. He slams home and locks, his entire body going rigid. Izuku feels the hot, liquid rush, another scalding flood joining the first, filling him until he feels impossibly, achingly full. Katsuki groans, a long, low sound of pure satisfaction, as he pumps his release deep into Izuku’s womb.

They collapse together, a heap of sweat-slick limbs and labored breath. Katsuki stays buried inside, his weight a possessive anchor. Izuku feels the subtle, continuous twitch of Katsuki’s cock as it empties the last of his spend.

“Feel that?” Katsuki murmurs into his damp hair, his voice rough. “That’s two loads. Packing you full.”

Izuku nods weakly, his cheek pressed into the wet sheet. The fullness is a profound, heavy warmth. He feels stuffed, claimed to his core. A spent, overwhelmed tear tracks through the sweat on his temple.

Katsuki shifts, finally sliding out. The sudden emptiness is a shock, a cold void. Izuku whimpers at the loss, at the immediate, hot trickle of cum that leaks from his used, gaping hole.

A large hand smacks his ass, sharp and stinging. “None of that. Turn over.”

Izuku obeys, his body moving with a boneless exhaustion. He rolls onto his back, wincing as the cool air hits his oversensitive flesh. Katsuki is kneeling between his legs, his cock still semi-hard, glistening with their mixed release. His red eyes are dark, hungry, scanning the wreckage of Izuku’s body.

“Look at you,” Katsuki says, his thumb swiping through the mess on Izuku’s inner thigh. He brings it to Izuku’s lips. “Taste it. Taste what we made.”

Izuku opens his mouth without hesitation, sucking Katsuki’s thumb clean. The taste is salty, musky, profoundly intimate. He meets Katsuki’s gaze as he does it, a fresh, submissive heat stirring in his gut.

Katsuki’s smirk is slow, predatory. “Still hungry, slut?”

Izuku nods, the movement frantic. He bucks his hips up, a desperate, weak little thrust against nothing. “Yes—please, Dynamight, fuck my gaping cunt! I need more, please!” His voice is a raw, used-up scrape, but the need in it is pure fire.

Katsuki’s smirk deepens. He doesn’t mount him again. Instead, he shifts, lying down on his side and pulling Izuku’s spent body back against his chest. He spoons him, the heat of his front searing into Izuku’s back. One large hand hooks under Izuku’s knee, lifting his leg high and wide, exposing him utterly.

“Such a greedy little hole,” Katsuki murmurs, his lips against Izuku’s ear. His other hand guides his cock, the thick, slick head nudging against Izuku’s oversensitive, leaking entrance. “Dripping my cum and begging for another serving. You’re insatiable.”

He pushes in. It’s a slow, relentless slide. Izuku is so loose, so thoroughly opened, that there’s no resistance, only a deep, full ache as he’s filled again. A broken sob escapes him. “Kacchan…”

“That’s it,” Katsuki growls, beginning a lazy, grinding rhythm. His thrusts are deep and possessive, each one a claim on the warmth his own release has left inside. “Take it. Your cunt was made for this. Made to be stuffed full of me.”

Izuku clutches at the sheets, his head falling back against Katsuki’s shoulder. The angle is different, deeper in a way that makes his breath hitch. Every drag strokes something profound and electric inside him. “Feels… feels so deep.”

“It is.” Katsuki nips at his earlobe. “I’m in your womb, slut. Painting it white again. You feel that heat? That’s me marking you from the inside.” His hand on Izuku’s thigh tightens, holding him open, immobile. “My good boy wife. My perfect little breeding bitch.”

The filthy words coil in Izuku’s belly, a different kind of penetration. He whimpers, his own hips trying to meet the slow, devastating thrusts. “Yours,” he gasps. “All yours. Breed me, please, I want it—”

“You’ll get what I give you.” Katsuki’s pace picks up, the wet slap of skin filling the room. “And you’ll thank me for it.”

“Thank you, Kacchan,” Izuku moans, the obedience immediate, fervent. “Thank you for fucking me, thank you for filling me—”

Katsuki groans, a low rumble of approval against Izuku’s spine. “Smart boy. You learn so fast.” He drives in harder, his rhythm losing its laziness, turning purposeful and punishing. “Gonna keep you. Gonna fuck you every night until you’re round with my kid. You want that? Want everyone to see my claim on you?”

Izuku’s vision blurs. The overstimulation is a live wire, but the pleasure is a tidal wave, drowning out the pain. His body is clenching again, a tired, involuntary pulse around the massive cock spearing him. “Yes! I want it, I want everyone to know I’m yours, that Dynamight fucks me—”

“Damn right.” Katsuki’s breath is coming faster now, his thrusts turning ragged. “Say it again. Who do you belong to?”

“You! Kacchan, I belong to you!” Izuku cries out, the confession tearing from him as another climax begins to gather, a slow, deep-building pressure different from the sharp bursts before.

“Fuck,” Katsuki snarls. He slams home and grinds, his hips making tight, circular motions that make Izuku see stars. “Come for me. Squeeze my cock with that pretty, used-up cunt. Milk me dry.”

The command is all it takes. Izuku shatters, his body bowing in Katsuki’s grip. This orgasm is a deep, rolling quake, a full-body convulsion that has him squirting again, a hot rush that slicks their thighs and the sheets beneath. His channel spasms, a frantic, fluttering rhythm around Katsuki’s length.

Katsuki curses, his own control fraying. He pistons into the clutching heat twice, three times more, then buries himself to the hilt with a guttural roar. Izuku feels the hot, liquid pulse, another scalding flood joining the mess already inside him. Katsuki holds himself there, throbbing, as he empties himself with a long, shuddering groan.

They don't stop. The night blurs into a brutal, wet rhythm of possession and surrender. Katsuki fucks him again, and again, and again—on his back, on his knees, bent over the edge of the bed—each round a little slower, a little rougher, as exhaustion bleeds into their muscles but the need doesn’t dim. Izuku loses count of the times he comes, his body reduced to a shuddering, oversensitive vessel, each climax a weak, squirting pulse that only makes Katsuki growl and thrust deeper. He loses count of the scalding floods that fill him, until he’s sloshing with it, a sticky, leaking mess.

“Can’t,” Izuku sobs, near dawn, his face pressed into a damp pillow. He’s on his stomach, Katsuki’s immense weight pinning him, another relentless, deep-stroking invasion moving his whole body with each thrust. “Kacchan, I can’t take anymore, it’s too much—”

“You can.” Katsuki’s voice is hoarse, raw with use and satisfaction. He wraps a hand in Izuku’s curls and pulls his head back. “You will. My bitch doesn’t get to say ‘can’t’. You take every drop I give you. You feel that?” He grinds deep, making Izuku whimper at the profound, aching fullness. “That’s my claim. Settling in your womb. You’re packed so full of me, you’ll taste it for a week.”

Izuku’s protest dies in a broken moan. His body, traitorous and well-trained, clenches weakly around the thick cock, another thin trickle of pleasure sparking through the exhaustion. “Y-yours,” he slurs, the obedience etched into his bones now.

Katsuki’s final release is a slow, shuddering pulse, more a hot seep than a flood. He collapses atop him, a sweaty, heavy blanket of muscle and scent. For a long time, the only sounds are their ragged breaths and the distant hum of the city below. Katsuki doesn’t pull out. He rolls them to their sides, keeping Izuku impaled, and wraps both arms around his chest, locking him in a vise.

Izuku’s consciousness flickers. He’s aware of the sticky sheets, the ache in every joint, the profound, liquid weight in his belly. He’s aware of Katsuki’s heartbeat against his back, steady and strong. “Dynamight…” he whispers, the name a prayer, a surrender.

“Sleep, fanboy,” Katsuki murmurs into his hair, his voice finally soft. The command is absolute. Izuku’s eyes close. Held tight in the dark, filled and owned, he falls into a deep, dreamless sleep.