The bed is too big. Masaru lies on his back in the center of the mattress he’s shared with Izuku for twenty-five years, and the cold, empty space on Izuku’s side feels like a geographical feature. A canyon. He stares at the ceiling, his hands limp at his sides. The house is quiet, the kind of deep quiet that amplifies every tiny sound. The hum of the refrigerator. The groan of a pipe. The slow, heavy tick of the hallway clock. And then, the other sound.

It’s a rhythmic, wet slap. Muffled by a wall and twenty feet of hallway, but unmistakable. It comes from Katsuki’s room. Followed by a low, shuddering moan he knows better than his own voice.

Izuku.

Masaru’s breath hitches. His fists clench in the duvet. He should get up. He should put on his robe, march down the hall, and… and what? He saw. He knows. He knelt. The memory is a hot brand behind his eyes: the taste, the submission, the way his own body betrayed him. A deep, shameful heat coils in his gut. His cock, soft and pathetic against his thigh, begins to thicken.

“No,” he whispers to the dark room. The word is paper-thin.

Another sound carries. Katsuki’s voice, a guttural, possessive growl too low to decipher the words, but the tone is clear. It’s the sound of ownership. Then Izuku cries out—a sharp, broken sound that dissolves into a pleading, gasping string of “yes, yes, yes.”

Masaru’s eyes sting. He turns his head into Izuku’s pillow. It smells like him. Like vanilla and green tea and the faint, sweet scent of his shampoo. The scent of his wife. The man who raised their son together. The man who is now down the hall, taking their son’s cock with a shamelessness that makes Masaru’s chest crack open. His own arousal is a traitor, a live wire of humiliation and need. He’s fully hard now, his length trapped against his stomach, heavy and aching.

“Stop,” he breathes into the pillow. “Just stop.”

But they don’t. The wet slapping speeds up. Izuku is sobbing now, but they’re not sounds of pain. They’re sounds of ruinous, overwhelming pleasure. Masaru knows the difference. He’s heard Izuku’s quiet sighs, his polite little hums of contentment in this very bed. He’s never heard this. This is a animal sound, a sound of being utterly unraveled.

His hand moves. He doesn’t tell it to. It slides down his own stomach, over the coarse hair, and wraps around his aching cock. The touch is electric, a jolt of pure shame that makes him whimper. He’s hard as stone, leaking. He listens to his wife getting fucked by his son, and he strokes himself.

“I’m sorry,” he chokes out, to the empty room, to Izuku’s ghost in the pillow. His hips jerk up into his own fist. The friction is too good. It’s a punishment. It’s a reward. He can’t tell anymore. He pictures it—Katsuki’s powerful body driving into Izuku’s softness, the way Izuku’s small breasts must be bouncing, the way his plump lips must be parted in a scream.

Down the hall, the sounds reach a fever pitch. A deep, ragged roar from Katsuki. A shattered, continuous wail from Izuku that climbs and climbs. The headboard hits the wall in a frantic, final tattoo.

Silence. A heavy, breathing silence.

Masaru’s hand stills. He’s panting, on the edge, his body trembling with need and self-loathing. He waits. He listens for the aftermath. A soft murmur. A low laugh. The sound of a kiss. The proof of intimacy. He hears it, and his thumb swipes over the slick head of his cock. He’s a stranger in his own home. A cuckold in his own bed. And his dick is throbbing, desperate for release, as he eavesdrops on the ruins of his life.

The shame curdles, thick and sour, in his throat. Masaru’s hand falls away from his cock. He sits up, the duvet pooling around his waist. His erection stands, obscene and undeniable, in the dim light from the hallway. The murmurs from Katsuki’s room have faded into a soft, shared silence that feels more intimate than the fucking.

He gets up. His legs are unsteady. He doesn’t grab his robe. He walks naked into the hallway, his bare feet silent on the polished wood. The light is on under Katsuki’s door.

He doesn’t knock. He turns the handle and pushes the door open.

The scene is a tableau of ruin. His ruin. Katsuki’s room is dim, lit by a single bedside lamp. Katsuki is sitting up against the headboard, naked, sweat gleaming on his defined chest. Izuku is curled against his side, head on Katsuki’s shoulder, the sheet pulled up to his waist. His green curls are damp with sweat, his face flushed and peaceful. They both look up as the door opens.

For a long second, no one speaks. Masaru stands in the doorway, naked, his body still humming with unwanted arousal, his cock half-hard between his legs. He sees the marks on Izuku’s neck. He sees the way Katsuki’s arm is possessively draped around Izuku’s bare shoulders.

“Couldn’t sleep, old man?” Katsuki’s voice is a low, satisfied rumble. He doesn’t move to cover himself. His crimson eyes rake over Masaru’s exposed body, lingering on his erection with a smirk.

Izuku shifts, pulling the sheet a little higher. “Masaru…” His voice is hoarse, used. There’s no guilt in it. Just a quiet, maternal concern that feels like a knife. “Are you alright?”

“Alright?” Masaru’s voice cracks. He takes a step into the room. The air is thick with the smell of sex—musky, salty, intimate. “I can hear you. All the way down the hall.”

“So?” Katsuki says. He strokes Izuku’s arm absently. “We weren’t being quiet.”

“This is my house.” The words are pathetic, even to Masaru. “My wife. My bed is empty.”

Izuku’s green eyes soften with a pity that burns worse than hatred. “I’m sorry you’re lonely.”

“Lonely?” Masaru barks a broken laugh. He gestures weakly at his own body, at his traitorous cock. “You think this is loneliness? I was… I could hear every sound. I listened. And I…” He can’t say it. The admission dies in his mouth.

“You got hard,” Katsuki finishes for him, his tone flat, analytical. “You jerked off. To the sound of me fucking your wife.” He says it like he’s stating the weather. “You're a cuck. That's what you're supposed to do.”

Izuku shifts, letting the sheet fall away as he stands from the bed. He walks, naked and unselfconscious, his soft body still glistening in the lamplight, and stops in front of Masaru. He reaches up, his small hands framing Masaru’s face. “I’m so sorry,” Izuku whispers, and he leans in, pressing a gentle, closed-mouth kiss to Masaru’s lips. It tastes like salt and Katsuki. “But this is our family now.”

Masaru’s eyes are wide, damp. He doesn’t pull away. He can’t.

“My purpose is to love our son,” Izuku continues, his voice a soft, maternal murmur. His thumbs stroke Masaru’s cheeks. “To take care of his every need. I still love you, Masaru. I do. But the love I feel for him… the lust…” He shakes his head, a small, awed smile touching his swollen lips. “It’s so much more.”

His gaze travels down Masaru’s body, lingering on his erect cock. The smile widens, genuine and terrifying. “Look at you. You never used to get this hard for me. Not like this. Your body… it loves this arrangement, doesn’t it?”

From the bed, Katsuki watches, a dark king on his throne. He doesn’t move, but his crimson eyes are fixed on Izuku’s hands on Masaru’s face.

Izuku turns his head, looking back at Katsuki over his shoulder. “Kacchan. We should fuck again. For Masaru. So he can cum.”

“Obviously,” Katsuki says, the word a low rumble of agreement. He pushes the sheet fully aside, revealing his body again. He’s already half-hard, his thick cock resting against his thigh. “Get over here, Mommy.”

Izuku gives Masaru one last, pitying look before turning and walking back to the bed. He climbs onto the mattress, kneeling beside Katsuki, and leans down to kiss his son deeply, one hand sliding into Katsuki’s spiky hair. The wet sound of their kiss fills the silent room.

Masaru stands frozen in the doorway, his cock throbbing. He watches his wife’s tongue slide into their son’s mouth. He watches Katsuki’s large hand come up to cup the back of Izuku’s head, holding him there. The command in the gesture is absolute.

“Don’t just stand there,” Katsuki grunts, breaking the kiss. He looks past Izuku, his eyes pinning Masaru to the spot. “You want a show? Kneel. Where I can see you.”

A violent tremor runs through Masaru. The order is a shock of cold water and burning shame. His legs buckle. He doesn’t decide to move. His body obeys, lowering him to his knees just inside the doorway, on the hard wooden floor.

“Good,” Katsuki says, and the praise is a brand. He grips Izuku’s hip, guiding him to straddle his lap. Izuku goes willingly, settling over Katsuki’s thighs, his back to Masaru. Masaru has a perfect view of the freckles scattered over Izuku’s shoulders, the soft curve of his waist, the full, perfect swell of his ass.

Katsuki’s hands slide around Izuku’s waist, pulling him close. He nuzzles into Izuku’s neck, his voice a hot murmur against the skin. “Show him, Mommy. Show him how wet you are for me.”

Izuku obeys. He arches his back, tilting his hips up off Katsuki’s lap, presenting himself to Masaru. His small hands reach back, fingers spreading the slick, swollen lips of his cunt apart. The lamplight glistens on the mess of arousal there, dripping down onto Katsuki’s thighs. “See, Masaru?” Izuku breathes, his voice thick with want. “See how wet he makes me?”

Katsuki’s hands tighten on Izuku’s waist, holding him in the display. He looks over Izuku’s shoulder at his kneeling father. “He has a kink, you know. My perfect mommy. Loves to be watched. Loves an audience.”

Masaru’s eyes are glued to the obscene, wet presentation of his wife’s pussy. He doesn’t blink.

“We fucked in front of that big front window, old man.” Katsuki continues, his voice a low, conversational rumble against Izuku’s spine. “Pinned him right against it. Broad daylight. Whole fucking neighborhood got a show.” He grinds his hips up, making Izuku gasp as the head of his cock nudges the exposed entrance. “Took his ass. First time. He screamed so loud. Came so hard he squirted like a broken hose all over the glass. It was beautiful.”

Katsuki brings one hand down in a sharp, cracking spank against Izuku’s ass. The sound echoes in the room. Izuku cries out, his body jolting forward, his cunt clenching visibly. “Mommy loves to be watched,” Katsuki reiterates, his voice dropping to a possessive growl. “And you’re gonna watch.”

In one powerful motion, Katsuki lifts Izuku off his lap and stands from the bed. He maneuvers Izuku’s body effortlessly, locking his arms under Izuku’s thighs and around his chest, holding him aloft in a crushing full nelson. Izuku’s back is pressed flat against Katsuki’s chest, his legs hooked over Katsuki’s arms, his dripping cunt positioned right in front of Masaru’s face, mere inches away.

Katsuki doesn’t hesitate. He adjusts his stance and drives his hips forward, sheathing his thick cock into Izuku’s soaked pussy in one brutal, deep thrust. Izuku’s head snaps back against Katsuki’s shoulder, a shattered scream tearing from his throat.

“You’re welcome, cuck,” Katsuki grunts, already setting a punishing, relentless rhythm, fucking up into Izuku’s body where Masaru can see every inch of penetration, every wet slide. The slap of skin is loud, obscene. Izuku’s small breasts bounce with each impact, his nipples hard and dark.

Masaru says nothing. His hand moves to his own cock, wrapped around the shaft in a white-knuckled grip. He starts jerking off, his strokes frantic and shameful, his eyes wide and unblinking as he watches his son violently claim his wife’s body right before him.

“Look at him, Mommy,” Katsuki pants, his breath hot against Izuku’s ear, his thrusts never slowing. “Look at your husband. Getting off on watching me fuck you.”

Izuku, trembling in the brutal hold, forces his tear-filled green eyes open. He looks down at Masaru’s face, at the agonized arousal etched there, at the fist flying on his cock. A broken, ecstatic smile touches Izuku’s lips. “He’s… he’s so hard, Kacchan,” he whimpers, the words punched out with each thrust.

“Of course he is,” Katsuki snarls. His crimson eyes lock with Masaru’s over Izuku’s shoulder. “This is what you are now. This is all you’re good for. Watching. Jerking off. Cleaning up the mess.” He punctuates each sentence with a deeper, harder drive of his hips, making Izuku sob with pleasure.

“Lick,” Katsuki grunts, his thrusts never faltering, each deep drive pushing Izuku’s dripping cunt closer to Masaru’s face. “Clean your wife. Clean my cock. Do it.”

Masaru doesn’t hesitate. A broken sound escapes him—part sob, part hunger—and he leans forward off his knees, his tongue extending. He licks a desperate, broad stripe over the place where his son is buried inside his wife. The taste floods his mouth: salt, musk, the tang of Izuku’s slick and the faint bitterness of Katsuki’s pre-come. He moans, the vibration against their joined flesh making Izuku cry out.

“Good cuck,” Katsuki pants, his hips snapping harder, forcing Masaru’s tongue to work faster to keep up. “This is what you were always meant for. To service us. To watch me wreck this pussy and then clean up the mess.”

Masaru’s eyes are glazed, his own forgotten cock leaking onto the floor. He laps hungrily at Izuku’s swollen lips, at the base of Katsuki’s shaft where it disappears, his tongue seeking every drop. He can feel the heat, the violent friction of his son’s thrusts against his mouth.

“He’s so hungry, Kacchan,” Izuku whimpers, his head lolling back. His green eyes are slits of pure ecstasy, watching his husband’s frantic worship. “He loves the taste of you inside me.”

“Of course he does.” Katsuki’s voice is thick with exertion and contempt. He slows his rhythm, grinding deep, letting Masaru’s tongue press against the stretched ring of muscle around his cock. “This is the perfect arrangement. I get my perfect mommy. Mommy gets fucked properly, gets bred like he needs. And you?” He chuckles, a dark, satisfied sound. “You get to be the family dog. You get to eat our leftovers and jerk off in the corner.”

Masaru moans again, the filthy words searing into him even as they make his own neglected cock twitch painfully. He suckles at Izuku’s clit, earning a sharp, gasping cry, his tongue working in time with Katsuki’s shallow, grinding thrusts.

“You were never enough for him,” Katsuki says, conversationally, as if discussing the weather. He pulls almost all the way out, letting Masaru’s tongue chase the glistening length of his cock before slamming back in. Izuku screams. “You provided. You fucked him politely in the dark. But you never *took* him. You never made him scream. You never made him cum. You never made him satisfied.”

“I’m yours,” Izuku sobs, the words a mantra. “Yours, Kacchan, only yours.”

“And he’s ours,” Katsuki says, his crimson eyes burning down at his father’s avid, tasting mouth. “Aren’t you, old man? Our good little cuck. This is your family now. This is your perfect marriage.”

Katsuki’s pace turns brutal again, piston-fast and deep. Masaru can’t keep up, his tongue lapping at the slapping wetness, his face slick with their fluids. He’s panting, drooling, his own arousal a painful throb of need between his legs.

“I’m gonna fill him,” Katsuki snarls, the words guttural. “Gonna pump my cum so deep into mommy’s womb it’ll take. You can lick that up, too. When it drips out of him. You can have whatever spills. That’s your share.”

Izuku’s body goes rigid, a silent, open-mouthed scream tearing through him as his orgasm hits. His cunt clenches viscously around Katsuki’s cock, a fresh gush of fluid soaking Masaru’s chin. Katsuki roars, driving in one last, punishing time, and holds, his whole body shuddering as he empties himself inside Izuku’s trembling body.

Katsuki’s cock slips from Izuku’s spent body with a wet sound, but he doesn’t lower him. He keeps Izuku suspended in the crushing hold, both of them panting, dripping onto the floor between them and onto Masaru’s upturned face. Katsuki’s crimson eyes are hazy with release, but sharp with a new, dark idea. “You need to piss, Mommy?” he murmurs into Izuku’s damp curls.

Izuku, boneless and trembling, gives a weak, shivering nod against Katsuki’s shoulder. “Y-yes, Kacchan.”

“Good. Me too.” Katsuki’s gaze drills into his kneeling father. “We’ll water our cuck. Give him a drink.”

Masaru doesn’t move. He doesn’t protest. A strange, terrifying calm descends over him. His own neglected cock aches, weeping a pathetic bead of pre-come onto the wood. When Katsuki shifts Izuku’s weight in his arms, angling their bodies, Masaru surprises himself. He leans back on his heels, opens his mouth, and tilts his head up like a baby bird.

“Look at that,” Katsuki breathes, a dark thrill in his voice. “He knows his place. Open wide, old man.”

The first hot stream is Izuku’s. It arcs down, splashing across Masaru’s cheek, his chin, into his open mouth. It’s warm, slightly bitter, utterly intimate. Masaru gags once, then forces his throat to work, swallowing as it pours over his tongue. His eyes slide shut.

Katsuki’s joins a second later, stronger, fiercer, hitting Masaru’s forehead, mixing with Izuku’s in a torrent that soaks his hair, his face, his chest. The combined warmth is a baptism. The taste floods him—salt, acid, the profound tang of their bodies, of their union, of his own ultimate degradation. He drinks it.

And that’s what does it. The shame is a live wire. The submission is complete. The taste of their piss on his tongue, the feel of it painting his skin, the sound of their relieved sighs above him—it snaps the last thread. Masaru’s spine arches. A broken, silent scream stretches his piss-wet lips. His untouched cock jerkes violently, once, twice, spilling his release in thick, helpless stripes across his own belly and the soiled floor between his knees.

The streams taper off. Dripping. Heavy breathing. Masaru slumps forward, catching himself on his hands, shuddering through the aftershocks of his humiliating climax, his face pressed to the wet wood.

“Fuck,” Katsuki says, his voice full of awe and contempt. He finally lowers Izuku, setting him gently on his feet but keeping an arm around his waist to steady him. “He came. Didn’t even touch himself. Just from being our fucking toilet.”

Izuku stares down at his husband, his green eyes wide. He sees the tremors, the spend, the utter ruin. Something twists in his chest—pity, horror, a fierce, possessive pride. He leans into Katsuki. “He’s perfect,” Izuku whispers, the words meant only for his son.

Katsuki kisses Izuku’s temple. “Yeah.” He looks at the mess of a man at their feet. “Clean yourself up, cuck. Then clean the floor. Our room smells like you now.”

Masaru doesn’t look up. He just nods, a slight, defeated motion, his cheek sticking to the floor.