Izuku’s love for Katsuki had always been a physical thing. It lived in the memory of a small, warm body tucked against his chest after a nightmare, in the ache of his arms after hours of rocking a colicky infant, in the permanent callus on his thumb from smoothing back spiky blond hair. For eighteen years, Katsuki had been his sun, and Izuku had happily orbited, a planet defined by his gravity. The boy demanded everything—attention, praise, touch—and Izuku gave it, pouring himself into the role of mother with a devotion that felt like the only truth his body had ever known. Their closeness was a language: Izuku’s soft hums, Katsuki’s childhood nickname ‘Kacchan’ spoken like a prayer, the easy way the teen would still slouch against him on the couch, a heavy, warm weight Izuku cherished.
That weight was gone now. The distance had begun as a chill, subtle as the first autumn wind, the day Izuku, hand pressed to his still-flat stomach, had smiled and said, “You’re going to be a big brother, Kacchan.” Katsuki hadn’t yelled. He’d just gone very still, his crimson eyes flicking from Izuku’s face to his belly and back, before muttering, “Cool,” and walking upstairs. The door to his room clicked shut. It had been clicking shut ever since.
Now, six months in, the chill was a frozen silence. Izuku’s belly was a firm, undeniable curve, a new planet forming in their solar system, and Katsuki acted like it was a foreign object. He stopped coming into the kitchen while Izuku baked. He ate dinner in three minutes flat, eyes on his phone. He stopped calling him ‘Mom’. The loss was a constant, hollow ache beneath Izuku’s ribs, sharper some days than the round ligament pain. He’d try to bridge the gap with cupcakes, with questions about basketball, with a hand on a tense shoulder that was instantly shrugged off. Each rejection was a tiny puncture in the vessel of him, leaking the steady confidence of his motherhood.
And then the panties started vanishing. The pretty ones, the lace and silk ones that made him feel soft and desirable under his homemaker’s clothes, a secret for himself and Masaru. He’d blame the laundry, then the dryer, then his own pregnancy brain. But the drawer grew emptier. A black lace pair. A pale blue satin. The red ones Masaru loved. He’d stood in front of the bureau last week, counting, a cold dread pooling in his gut. What was happening to them?
Izuku stood in the master bedroom, his hand resting on the firm swell of his belly, listening to the water run in the master bath. Masaru was getting ready for bed. The cedar floor was cool under his bare feet, a contrast to the hot unease coiling in his chest. He took a breath, the soft silk of his robe brushing his thighs, and pushed the door open.
The steam from the shower curled out, smelling of Masaru’s sandalwood soap. His husband stood at the sink in pajama pants, wiping fog from his glasses with the edge of his t-shirt. Izuku leaned against the doorframe, the weight of the baby a constant, grounding pressure. “Masaru?”
“Hmm?” Masaru settled his glasses back on his nose, his brown eyes softening when they landed on Izuku. His smile was warm, automatic. “Everything okay?”
“Have you… seen any of my panties?” The question felt absurd the moment it left his lips. His voice was too quiet, almost drowned by the drip of the showerhead. “The nice ones. The lace. They keep… disappearing from my drawer.”
Masaru’s brow furrowed slightly. He turned fully, giving Izuku his full attention, a habit of his. “Disappearing? Like, in the laundry?” He adjusted his glasses, a small, familiar gesture. “You know, with the pregnancy, your memory’s been a little…”
“It’s not my memory.” Izuku cut in, sharper than he intended. He pressed his palm flat against the curve of his stomach, as if to calm the flutter inside—or himself. “I’ve counted. The black lace with the bow. The blue satin. The red ones you bought me for our anniversary. They’re gone. Not misplaced. Gone.”
A beat of silence hung between them, thick with the humid air. Masaru studied him, the kind concern in his eyes deepening into something more searching. “That’s… strange. You’re sure they’re not just tangled in another load? Or maybe Katsuki needed a rag for something and grabbed the wrong thing?”
“Katsuki wouldn’t.” The denial was immediate, visceral. The thought of his son, his distant, cold son, touching those intimate scraps of silk made something icy trickle down Izuku’s spine. “He wouldn’t do that.”
“I’m just trying to think logically, Izuku.” Masaru’s voice was a gentle placation. He reached out, his hand warm and solid on Izuku’s shoulder. “It’s probably nothing. We’ll find them. Or we’ll buy more. Don’t let it stress you out, okay? You’ve got enough on your mind.”
His thumb stroked the knot of tension in Izuku’s neck. The touch was meant to soothe, but it felt like a dismissal. The logical explanation. The pregnant wife getting forgetful. Izuku leaned into the touch anyway, closing his eyes for a second. He wanted to believe it. He wanted this to be a silly, hormonal mystery.
But the cold dread in his gut had crystallized into a hard, knowing shard. This wasn’t about laundry. This was about the silent, locked door down the hall. This was about the way Katsuki’s eyes skittered away from him now, as if Izuku’s very body was an accusation. The missing panties were a symptom, a physical clue to a sickness he couldn’t name.
“Yeah,” Izuku whispered, his voice hollow. “You’re probably right.”
He forced a small smile for Masaru, the perfect, worried homemaker. But inside, his thoughts were a frantic, scrambling thing. *Where are they? What is he doing with them? My baby boy. What’s happening to you?* The questions looped, a silent scream that filled the space between the drip of the faucet and the distant, absolute quiet of Katsuki’s room.
Izuku forces the smile to stay on his face until Masaru’s hand drops from his shoulder and his husband turns back to the sink. The moment the connection breaks, the expression dissolves. The hollow agreement hangs in the steamy air, a lie they both pretend to believe. He listens to Masaru brush his teeth, the rhythmic scrape a mundane soundtrack to the chaos in his skull. *Check on him. Just check. See if his light is on. Maybe he’s awake. Maybe he’ll talk.* The thought is a desperate, fluttering bird.
He pads out of the bathroom on bare feet, the cedar floorboards cool and familiar. The hallway stretches, dark except for the sliver of light under their bedroom door. At the far end, Katsuki’s door is a slab of deeper shadow. No light seeps from beneath it. Absolute quiet. Izuku’s hand finds the swell of his belly, a self-soothing gesture. The baby kicks, a soft flurry, and the ache in his chest sharpens. *Used to love feeling him move.*
He moves down the hall, each step a conscious effort toward the silence. The house feels too still, a held breath. He stops outside Katsuki’s door. The wood is solid, painted a dark, glossy black years ago by a teenager asserting his independence. Izuku raises his hand, knuckles poised to knock. He hesitates. The last time he knocked, two days ago, the only answer was a growled, “Busy.”
Instead, his fingers curl around the cool metal of the doorknob. It’s unlocked. The realization is a jolt. Katsuki has been locking it religiously for months. The simple, unengaged turn of the mechanism feels like a trap, or an invitation. Izuku’s breath hitches. *Maybe he’s asleep. Maybe he just forgot.* He pushes, just a crack. The door swings inward silently on well-oiled hinges.
The world Izuku knows fractures along the edge of light. A soft, low lamp glows beside Katsuki’s bed, painting the room in amber and long, desperate shadows. The smell hits him first—not the typical teenage boy musk of sweat and cheap cologne, but something saltier, animal, layered with the faint, floral detergent Izuku uses. Then the sound: a wet, rhythmic slap, fast and frantic, underscored by ragged, choked breathing.
Izuku’s eyes adjust, and the image resolves with cruel, crystalline clarity. Katsuki is naked on his back in the center of his rumpled bed, muscles corded with tension. One hand is fisted around the base of his cock—a thick, flushed length Izuku’s brain recoils from recognizing—and wrapped around his knuckles, pulled taut, is a scrap of black lace. Izuku’s black lace. The bow is crushed. The other hand is pressed to Katsuki’s face, holding a wad of red silk against his nose and mouth. His son’s eyes are screwed shut, his hips pumping up into the tight tunnel of his own fist and the stolen fabric.
“Mmh—ah—nngh—” The sounds are guttural, needy. They are not the sounds of his basketball captain son. They are the sounds of a child in the grip of a fever. Katsuki’s abdomen tightens, his heavy balls drawing up, and he grinds his hips harder, the wet noise growing slicker. He buries his face deeper into the red silk, inhaling with a desperate, shuddering gasp.
Then the voice. High. Whimpering. Shattered. “Mommy… Mommy, please…”
The word lodges in Izuku’s chest like a shard of glass. He sways, his fingers digging into the doorframe to keep his knees from buckling. The baby inside him rolls, a violent, startled motion. *My panties. On his face. On his…* His mind stutters, refuses the completion of the thought. This isn’t happening. This is a nightmare born of his own anxiety, a grotesque hallucination conjured by the hollow ache Katsuki left in him.
But the evidence is there, moving, alive with his son’s perverted need. Katsuki’s pace becomes frantic, punishing. “Mommy, I’m— I’m gonna—” he sobs, the child-voice breaking. His back arches clear off the bed, a bowstring pulled to snapping. His fist becomes a blur. The lace must be soaked, sticking to him, because the sound turns into a sticky, obscene squelch.
Izuku should leave. He should close the door. He should run. But his body is stone. His eyes are trapped. He is a witness to the unraveling of his firstborn, and some deep, maternal nerve—the one that always answers the cry, no matter what form it takes—holds him fast. *He’s hurting. He’s calling for me.* The realization is a poison that spreads warmth even as it kills.
Katsuki’s climax tears through him with a raw, wounded cry that is all little boy. “Mommy!” His body seizes, spine rigid, and Izuku watches, sickly fascinated, as streaks of white pulse over his own stolen lace, over his knuckles, onto the tense plane of his stomach. It goes on and on, Katsuki whimpering through each jet, his hips twitching weakly, until he collapses back into the mattress, spent and trembling.
For a long moment, there is only the sound of harsh, gulping breaths. Katsuki’s hand falls away from his face, the red silk panties dropping to his heaving chest. He stares at the ceiling, eyes glazed and wet. He looks young. Lost. The regressed child swimming in the aftermath.
His body moves before his mind can catch up, a silent retreat on autopilot. His fingers, numb and cold, ease the door closed until the latch clicks with a soft, final sigh. The image of his son—spent, trembling, painted with his own release and the evidence of his sickness—is seared onto the back of his eyelids. Izuku turns and flees.
The hallway stretches, a dark tunnel. His bare feet slap softly against the cedar, a frantic, stumbling rhythm. His heart is a wild, panicked bird trying to beat its way out of his ribs. He can still smell it—the salt, the musk, the floral detergent turned perverse. It’s in his nose, in his throat. He stumbles into the master bedroom, shuts the door behind him, and leans against it, his chest heaving.
*My baby boy. My Kacchan.* The words loop, a broken record of a lullaby. But the image that overrides them is clinical, obscene: the lace, the silk, the desperate, childlike begging. *Mommy.* The word echoes in the silent room, in the hollow of his skull. It wasn’t a title. It was a plea. A sick, twisted incantation.
Masaru is already asleep in their bed, breathing steady and deep, one arm curled around Izuku’s pillow. Izuku watches the rise and fall of his husband’s back for a single, suspended moment before he turns. He pads on silent feet across the room, past the bed, and into the adjoining bathroom. He closes the door. The lock clicks, a small, definitive sound in the quiet.
He leans back against the cool wood, his chest still tight. The robe’s silk belt is a loose knot at his waist. His fingers, clumsy and cold, fumble with it. The fabric gives, and the robe slides off his shoulders, puddling at his feet on the tile. He is naked. The air in the bathroom is still, cool against his flushed skin. He forces himself to turn toward the wide mirror above the sink.
The man—the mother—staring back is a stranger. His green curls are mussed, his round eyes wide and glassy with unshed tear landscaped. His gaze travels down, over the familiar of freckles scattered across his shoulders and chest, over the small, soft swell of his breasts with their dark pink nipples, hardened now from the chill or the shock, he doesn’t know. It drops to the pronounced curve of his belly, the skin stretched taut over the life inside. His hands, trembling, come to rest there. A shield. A lie.
His eyes drag lower, past the neat triangle of pubic hair, to the heart of the betrayal. His pussy is wet. Visibly, shamelessly wet. The lips are swollen, glistening under the harsh bathroom light. His clit is a hard, aching peak, twitching with a pulse that echoes the frantic beat of his heart. He stares, disbelieving. *No. This isn’t. I’m not.* But the evidence is there, a slick, physical truth. His body has responded to the obscenity. To the salt-musk smell that still feels lodged in his sinuses. To the image of his son, desperate and pleading. *Mommy.*
“What is wrong with me?” The man whisper scrapes out of his throat, raw and broken. He isn’t asking the mirror. He’s asking the part of him that is now slick and throbbing. The maternal core that heard a child’s cry—even a twisted, perverted one—and answered with a rush of heat. It was a response born of a lifetime of conditioning: *Kacchan needs you. Go to him. Soothe him.* But the need was a monster, and the soothing it demanded was unthinkable. And yet his body, traitorous and primal, had prepared for it.
He brings a hand down, fingers skirting the wetness. He doesn’t touch directly. He can’t. The shame is a live wire. His eyes squeeze shut, but the afterimage is brighterrz behind his lids: the black lace stretched taut, the desperate arch of Katsuki’s back, the final, sobbing cry. *He was hurting. He was calling for me. And I watched. I watched all of it.* The heat in his groin coils tighter, a sickening echo of his son’s climax. A sympathetic vibration to a forbidden frequency.
His knees buckle. He doesn’t fight it. He slides down the bathroom door until he’s sitting on the cool tile, his back against the wood, his legs splayed. The curve of his belly rests on his thighs. He looks down at himself again, at the wet evidence. A low, whimper of a foundation cracking. The perfect, caring stay-at-home mom. The patient, gentle mother. That man is gone. In his place is this: a pregnant cunt dripping for his own son’s corruption.
“He needs help,” Izuku murmurs to the empty room, his voice a thread. “My baby boy needs… help.” But the words are hollow. What kind of help? Therapy? A lecture? The image that surfaces isn’t of a doctor’s office. It’s of him, walking back down that hall. Of pushing Katsuki’s door open all the way. Of crossing the room. Of what his son’s wild, guilty, yearning eyes would do if he saw him standing there. If *Mommy* answered the call.
The thought is a lightning strike. It jolts through him, and his hips jerk forward once, a tiny, involuntary grind against nothing. A sharp gasp punches from his lungs. His hand flies to his mouth, stifling it. He listens, terrified, but only Masaru’s steady breath comes from the bedroom. The guilt is a crushing weight. But beneath it, under the shame and horror, something else slithers, warm and dark. A terrible, maternal curiosity. *What would he do? What would he need me to do?*
His fingers, still pressed against his mouth, slide down. The taste of salt skin is sharp. He imagines the hallway beyond. Imagines standing up. Walking. The cool floor under his feet. The dark. The black door, unlocked.
“What if I went back?” The whisper is barely sound. His own voice frightens him. It’s too calm. Too considering.
His hand drifts lower, skims his trembling belly, and settles in the thick, damp curls between his legs. He doesn’t touch his clit, not yet. He presses the heel of his palm against his mound, and the pressure sends a bolt of pure, shaming heat straight to his core. A soft, ragged moan escapes his bitten lips. *He’s still there. He’s still warm. What would his face look like if I walked in?*
His index finger finds his slit. It’s slick, swollen lips parting for him. The contact is electric. His hips jerk again, a needy little thrust into his own touch. *He was so hard. So big. Wrapped in my things.* The thought isn’t a horror now. It’s a fuel. His finger circles his entrance, gathering wetness, the sound obscenely loud in the silent room.
“Mommy’s here,” he breathes to the empty air, testing the words. They taste like sin and syrup. His finger pushes inside, just the tip. His cunt clenches around it, greedy. *Is this what he wanted? Is this the soothing?* His mind paints the picture: him, standing in Katsuki’s doorway, robe open. His son’s shocked, guilty, hungry eyes. The way Katsuki’s spent cock would twitch back to life at the sight.
He adds a second finger, stretching himself. His breath comes in short, sharp pants. He pumps his hand slowly, the wet squelch a filthy echo of the sounds from down the hall. *He’d call for me. He’d say ‘Mommy’ just like that, broken and little. And I’d go to him. I’d climb onto that bed. I’d touch his face.*
His thumb finds his clit, a hard, throbbing pearl. He rubs it in tight, desperater circles. The pleasure is a white-hot wire, pulling taut from his navel to his knees. His back arches off the door, his pregnant belly a heavy, sacred weight. *I’d let him touch me. Here. I’d guide his big, clumsy hand. He’d be scared. He’d be so excited.*
“Kacchan,” he whimpers, the childhood name a secret between them. His fingers fuck into himself faster, curling, searching. His other hand grips his own breast, pinching the dark nipple. The dual sensation blurs everything—the cool tile, the sleeping husband, the moral world—into a haze of need. *He needs me. Only me. The baby won’t matter. I’d be his again.*
The fantasy crystallizes, cruel and perfect: Katsuki, on his knees between Izuku’s splayed thighs, face buried in his mother’s weeping cunt, drinking him down like a starving boy. Izuku’s fingers tighten in spiky blonde hair. *Yes. Like that. My good boy.*
A choked cry tears from his throat. His hips piston against his hand, mindless. The orgasm rips through him, violent and silent—a convulsion that locks his muscles and whites out his vision. Then, a hot gush. Not just release, but expulsion. He squirts hard across the cool tile, a jetting stream that hits the floor with a sharp, wet sound. Pleasure, sharp as shattered glass, floods his veins.
It’s followed instantly by a tsunami of shame so profound it steals his breath. The proof pools on the floor, undeniable.
He slumps against the door, boneless. His fingers slip out, wet and trembling. The aftermath is a physical sickness. The cool air hits his sweat-slicked skin, and he shivers. He stares at his glistening fingers, then at the wetness smeared on his inner thighs. Proof.