The old house settled around midnight, a symphony of creaks and sighs that Izuku knew by heart. He lay on his back in the queen bed, Shoto’s warm, solid weight pressed along his side, breathing deep and even in sleep. The single desk lamp was off now, plunging the room into a deep blue gloom, the shapes of his old All Might posters just shadows on the wall. He stared at the ceiling, willing his body to still, his mind to quiet. The smell of Shoto’s clean skin, of the fabric softener on the sheets, of childhood—it usually soothed him. Tonight, it felt like a cage.

A low murmur seeped through the wall.

Izuku froze. His eyes cut to the shared wall with the guest room. It was plaster and lathe, old and thin.

“...c’mon, Kats.” Eijiro’s voice, muffled but unmistakably pleading. “It’s been forever.”

“It hasn’t been forever.” Katsuki’s reply was a low, gruff rumble. “Go to sleep.”

“It has! Since that first night. We always do it every night. You know we do.” A rustle of sheets. “I miss you. Miss feeling you.”

Izuku’s breath caught in his throat. He became acutely aware of the space between his body and Shoto’s. The cold inch of sheet. The heat of his own shame, flooding up his neck.

“I’m tired, Ei.” Katsuki’s voice was flat. Final.

“You’re not tired. You’ve been ‘tired’ for two weeks. What’s going on with you?”

“Nothing’s going on. Just drop it.”

“I won’t drop it.” Eijiro’s tone shifted, playful but persistent. “My boy pussy’s getting lonely. Aren’t you gonna take care of it?”

A sharp, pained sound punched from Izuku’s lips, instantly stifled. He slapped a hand over his mouth. Shoto stirred slightly, mumbling, then settled. Izuku’s eyes burned. *Boy pussy*. The crude, affectionate term Eijiro used for himself. The term Katsuki knew. The term for a body that was, in its most basic configuration, like Izuku’s own.

Silence from the other room. Then a long, ragged exhale.

“Fuck,” Katsuki whispered, the word thick with surrender.

The sound that followed was a kiss. Not soft. Hungry. Wet. Izuku heard the smack of lips, a low groan—Eijiro’s—and the creak of bedsprings taking weight.

“Yeah,” Eijiro breathed, voice already gone hazy. “Just like that. Knew you wanted to.”

“Shut up,” Katsuki growled, but there was no heat in it. Just a desperate kind of focus.

Izuku’s hand slid from his mouth, trembling. He pressed his palm flat against the cold wall. He could feel a faint vibration. A rhythm.

More sounds. The slick, unmistakable noise of a mouth on skin. Eijiro’s sharp, happy gasp. “Oh, fuck, your tongue…”

Katsuki didn’t speak. His communication was the rustle of sheets, the shift of the mattress, a low, animal grunt of effort. Izuku knew that grunt. He’d felt it against his own throat, his own ear. He knew the weight of that body, the specific scent of Katsuki’s sweat when he was turned on, the way his breathing hitched just before—

“Inside,” Eijiro begged, voice cracking. “Please, Kats. Need you inside. Now.”

A beat. A hissed curse. Then the sound. The thick, wet, pushing sound of a cock entering a willing, eager body. Izuku flinched as if struck. His own pussy clenched, empty and aching, a traitorous pulse of heat that made him want to vomit.

“God, yes,” Eijiro moaned, loud and unashamed. “So deep. Fuck, I needed this. *We* needed this.”

The bed began a rhythmic, relentless knock against the wall. *Thump. Thump. Thump.* Each impact traveled through the plaster, through Izuku’s palm, up his arm, and lodged like a shard of glass in his chest.

Katsuki was fucking his husband. Properly. The way a husband should. In their marital bed. The sounds were of mutual pleasure, of a familiar, loving rhythm. Eijiro’s moans were bright, open things. Katsuki’s breaths were ragged, punctuated by soft, driving grunts with every thrust.

“You feel so good,” Eijiro gasped. “So big. Always so big for me.”

Izuku squeezed his eyes shut. Tears leaked hot down his temples, into his hairline. *He’s ten inches. Uncut. You know how it feels. You know.* The knowledge was a physical sickness. He pictured it. Katsuki’s powerful hips driving forward, Eijiro’s strong legs wrapped around his waist, their bodies moving together in a dance they knew by heart. A dance Izuku had just learned, in stolen, secret, shameful places.

“Harder,” Eijiro urged, his voice pitching higher. “C’mon, baby, give it to me. Wanna feel you tomorrow.”

The *thump-thump-thump* intensified. The wall vibrated steadily. Katsuki’s control was slipping; Izuku could hear it in the broken rhythm of his breathing, in a raw, choked-off sound that was almost a sob.

“Gonna come,” Eijiro cried out, not bothering to be quiet. “Katsuki, I’m gonna—!”

His voice shattered into a wordless, keening wail. The bed slammed against the wall in a frantic, final cadence. Izuku heard the wet, slapping sounds of skin on skin reach a fever pitch, heard Eijiro’s joyous, sobbing release.

And through it, Katsuki was silent. No roar. No claim. Just the brutal, efficient sound of his hips pistoning, chasing his own end.

It came a moment later. A deep, guttural groan that was all pain. A final, solid *thud* as he buried himself deep and stilled.

Silence.

Then heavy, panting breaths. The wet sound of a kiss. Eijiro’s blissful, sleepy murmur. “Love you. Missed that.”

No reply. Just more breathing. The creak of the mattress as someone shifted.

Izuku realized he was crying soundlessly, his whole body shaking. The heat between his legs was a cruel mockery. He was soaked, his small cunt clenching around nothing, his nipples hard and aching against his shirt. His body, the one that only squirted for Katsuki, was humming with betrayed, wretched want. And his heart… his heart was in splinters. He lay there, listening to the aftermath of married love, shattered by the proof that he was, and would only ever be, a filthy secret.

The sob tore from him like a rib cracking. Izuku scrambled from the bed, the comforter tangling around his legs. He didn’t look at Shoto’s sleeping form. He just ran. Out the door, into the dark hallway, his socked feet slipping on the hardwood. He slammed the bedroom door behind him with a crack that echoed through the silent house. He didn’t care. He needed air, needed out, needed to not be inside the walls that held that sound. He flew down the stairs, yanked open the front door, and stumbled onto the frigid porch.

The winter air was a physical slap. It stole his breath, sharp and clean, a brutal contrast to the thick, suffocating heat of his shame. He made it three steps before his legs gave out. He crumpled onto the old wooden porch swing, the chains groaning in protest. Then he broke. Great, heaving sobs wracked his frame, his face buried in his hands, snot and tears leaking through his fingers. It was ugly, uncontained, a complete collapse.

The front door opened and closed again, soft this time. A heavy tread on the porch boards. Izuku didn’t need to look up. He knew the shape of that silence, the weight of that presence. Katsuki stood there, barefoot in just a pair of sweatpants, his chest bare to the cold. He didn’t speak.

“Go away,” Izuku choked out, the words mangled by tears. “Go back to your husband.”

Katsuki didn’t move. “You slammed the damn door.”

“I don’t care! I heard you. I heard everything.” Izuku dragged his hands from his face, looking up at him. His eyes were swollen, his nose running. “You were… he was… and you…” He couldn’t form the sentence. It was just images. Sounds. The proof.

“I know you heard.” Katsuki’s voice was low, gravelly. He took a step closer. The cold was raising goosebumps on his skin, his nipples pebbled tight. “I was hoping you'd be asleep.”

“Hoped I was?” A hysterical laugh bubbled out of Izuku. “So it’s my fault? For listening? For existing in the next room while you fuck him?”

“Watch your mouth.”

“Or what?” Izuku shot to his feet, the swing jerking violently. “You’ll punish me? You already did. That was the punishment. Letting me hear how it’s supposed to be. How it sounds when you’re not hiding.”

Katsuki’s jaw tightened. In the moonlight, his face was all harsh angles and shadow. “It’s not like that.”

“It sounded exactly like that! He wasn’t quiet. He wasn’t ashamed. He called you ‘baby’.” The word tasted like poison. Izuku wrapped his arms around himself, shivering violently. “He gets to have you. Openly. He gets to fall asleep with your smell on him. I have to… I have to lie in bed next to Shoto and pretend I’m not… that I don’t feel you…” His voice dissolved into another wet gasp. “I’m just a secret. A filthy secret you jerk off to when you’re bored with your real life.”

“Stop it.” Katsuki closed the distance between them in two long strides. His hands came up, not to strike, but to grip Izuku’s shoulders. They were burning hot against the thin cotton of Izuku’s shirt. “You think that was for me? That was… maintenance. That was keeping a fucking peace you know nothing about.”

“It didn’t sound like maintenance.” Izuku tried to shrug him off, but the warmth was anchoring, a betrayal of his own body. “It sounded like love. It sounded like you wanted him.”

Katsuki’s fingers dug in, his crimson eyes blazing in the dark. “I have a husband. A life. What did you think this was, Izuku? A fairy tale? That I’d leave him for you?”

The bluntness of it was a new kind of blow. Izuku shook his head, fresh tears spilling. “No. I’m not stupid. I just…” He swallowed, the truth clawing its way up. “I didn’t think I’d have to hear it. I didn’t think it would feel like dying.”

The fight seemed to drain out of Katsuki. His grip softened, thumbs moving in small, unconscious circles on Izuku’s shoulders. He looked exhausted. Old. “I tried to put him off. You heard me try.”

“But you didn’t. You gave in. You fucked him. And I…” Izuku’s breath hitched. He looked down, ashamed. “My body… it reacted. Even while my heart was breaking, it got wet. It wanted. What’s wrong with me?”

Katsuki was silent for a long moment. The only sounds were Izuku’s ragged breathing and the distant whisper of wind through bare trees. Then, quietly, “Nothing’s wrong with you. It’s me. I’m what’s wrong. I poisoned this.” His hand came up, rough knuckles brushing a tear from Izuku’s cheek. The touch was terrifyingly gentle. “You shouldn’t be out here crying over someone like me.”

“I can’t help it,” Izuku whispered, leaning infinitesimally into that touch. “I don’t know how to stop.”

Katsuki’s hands on his shoulders guided him back, a firm pressure until the backs of Izuku’s knees hit the cold wood of the porch swing. He sank down, the chains groaning again. Katsuki sat beside him, his bare thigh pressing against Izuku’s pajama pants, and pulled him in without ceremony. Izuku went, collapsing against the solid, fever-hot wall of his uncle’s chest. Katsuki’s arms wrapped around him, crushing him close, one broad hand splayed between his shoulder blades.

The sobs hiccupped to a stop, choked off by the sheer reality of the embrace. Izuku shuddered, his face pressed into the hollow of Katsuki’s throat. He smelled like sex and sweat and cold night air. He smelled like Eijiro.

“I’m sorry, Izuku.”

The words were a low, rough vibration against Izuku’s temple. Then Katsuki’s lips pressed there, a dry, lingering kiss that held a weight Izuku had never felt from him before. It wasn’t hunger. It was a confession.

Izuku’s breath caught. He curled his fingers into Katsuki’s side, nails digging into cold skin. “Don’t,” he whispered. “Don’t apologize if you don’t mean it. If you’re just going to go back in there to him.”

“I mean it.” Katsuki’s hand moved up, tangling in his curls, holding his head in place. “I’m sorry you heard. I’m sorry you’re hurt. I’m sorry I’m the bastard who caused it.”

“You’re not sorry you did it.”

Katsuki was silent for a long moment. The wind cut across the porch. “No,” he said finally, the word stark and awful. “I’m not sorry I fulfilled my marital duty. I am sorry it carved you open. Both things are true.”

Izuku laughed, a broken sound. “You keep saying ‘duty’. It didn’t sound like duty. He sounded happy. You sounded… final.”

“It is final.” Katsuki’s thumb stroked the nape of Izuku’s neck. “It’s done. It’s over for the night. This… this here, with you shaking apart on my porch, this is what’s real right now.”

“It’s not real either,” Izuku said, the truth a cold stone in his gut. “This is just another secret. The cold, sad one that comes after the hot, dirty one.” He tilted his head back to look at Katsuki’s face. Moonlight caught the damp tracks on his own cheeks. “Did you think of me? When you were with him?”

Katsuki’s eyes closed. A muscle jumped in his jaw. “Don’t ask me that.”

“You have to answer. You owe me that.”

"Yes."

The word was flat. Final. Katsuki’s eyes opened, meeting Izuku’s, and there was no shield left in them. Just a horrible, naked truth. "Every single time. Every time I've fucked him, for years, I've thought of you. I close my eyes, and it's your face. Your sounds. Your fucking… everything."

Izuku’s breath vanished. The cold air felt like glass in his lungs.

"Every day of my marriage," Katsuki continued, the words coming now like a poison being drained. "I think of you. The day I married him, standing there in that stupid suit, all I could see was you. You were eighteen. You had frosting on your nose from the cake at the reception. I wanted to lick it off. I wanted to set the goddamn place on fire and carry you out of it."

"Stop," Izuku whispered, but it was soundless, a plea with no air behind it.

Katsuki didn’t stop. His hand fisted tighter in Izuku’s hair, not to hurt, but to hold him there, to make him hear it. "I met Eijiro a year before that. He was… bright. Kind. Uncomplicated. He reminded me of you. Not the way he looked. The way he felt. Hopeful. That was the closest I could ever get to having you. So I married him."

A broken, wet sound escaped Izuku’s throat. He felt nauseous. He felt seen. "You’re a monster."

"I know." Katsuki’s thumb stroked his cheekbone. "I built a whole life with a good man just to pretend it was a shadow of you. And I still have to steal pieces of you to get through it. The panties. The pictures. The memories. They’re all I have."

"You have him," Izuku choked out. "You have a husband who loves you. Who begs for you. And you use him… to think of me?"

"Yes."

The simplicity of it was the most devastating part. There was no justification. Just a fact. Katsuki’s other hand slid down, splaying over the small of Izuku’s back, pulling their bodies flush. Izuku could feel the hard line of Katsuki’s cock, still half-hard, trapped in his sweatpants. The evidence of his recent duty. The proof of his confession.