The cold floorboards of the office bit into Izuku’s bare knees. He kept his eyes on the worn rug, his naked body a trembling offering in the lamplight. The door opened, and Katsuki’s shadow fell over him—not the cassock now, but dark trousers and an unbuttoned shirt, his clerical collar stark against his throat. He circled, the heat of his gaze a physical brand on Izuku’s back, his hips, the vulnerable curve of his ass. A single, warm finger traced the line of his spine, and Izuku’s breath hitched, the world narrowing to that touch and the terrible, waiting silence.
“Look at you,” Katsuki’s voice was a low rumble in the quiet room. “Kneeling. Just like you should.”
Izuku flinched. His hands clenched into fists on his thighs. He couldn’t speak. The finger trailed lower, over the dip at the base of his spine, and his whole body tightened.
“What’s the matter?” Katsuki asked. He stopped circling, standing directly behind him. Izuku could feel the heat of him, could smell the faint scent of incense and something darker, metallic, on his skin. “Cat got your tongue? Or are you praying?”
“P-please,” Izuku whispered, the word cracking.
“Please what?” Katsuki’s hands settled on his shoulders, thumbs digging into the tense muscle. “Use your words, Izuku. Confess your need. It’s a sacrament.”
“This isn’t… this isn’t right.”
Katsuki’s laugh was soft, devoid of humor. “Right? You lied to God. You lie to everyone who looks at you. Your entire existence in my church is a beautifully constructed sin.” His hands slid down, over the sides of Izuku’s ribcage, making him jerk. “My only sin is wanting to touch it.”
His palms smoothed over Izuku’s hips, possessive and warm. They spanned the narrow width of him, fingers splaying across the soft skin of his lower belly. Izuku gasped, a sharp, shameful sound, as those hands pulled him back just an inch, his ass pressing against the hard line of Katsuki’s cock straining behind his trousers.
“You feel that?” Katsuki breathed into his ear. His voice had dropped to a velvet murmur. “That’s the truth. Your pretty little act makes me hard. Your secret makes me ache.” He rocked forward, a slow, deliberate grind, and Izuku moaned, a helpless, traitorous noise torn from his throat. “There it is.”
One hand slid around to his front, fingers threading through the dark green curls between his legs. Izuku cried out, trying to buck away, but Katsuki’s other arm banded across his chest, holding him fast. “Ssh. Let me feel.” His fingers explored, petting over the soft folds, finding the swollen, sensitive bud of his clit. Izuku shuddered, a wave of heat flooding through him, betraying him entirely. “So wet already,” Katsuki mused, his finger sliding through the slickness. “For me. In my office.”
“I d-didn’t—”
“You did.” Katsuki pressed a wet finger against his entrance, not pushing in, just resting there. A threat. A promise. “Your body doesn’t lie. Not like you do.” He withdrew his hand, and Izuku whimpered at the loss, the cold air a shock. Katsuki brought his glistening fingers to Izuku’s lips. “Taste. Taste your own corruption.”
Izuku turned his face away, eyes squeezed shut. Katsuki’s free hand fisted in his curls, forcing his head back. “Open.” The command was absolute. A tear traced a hot path down Izuku’s freckled cheek. His lips parted on a sob. Katsuki pushed two fingers inside his mouth. The taste was musky, salt-bitter, overwhelmingly his own. “Suck them clean,” Katsuki ordered, his voice rough. “Consider it your first penance.”
"I can't—" Izuku choked out, the words thick around Katsuki's fingers still in his mouth. His eyes swam with tears, green and desperate. "Please, Father, we can—"
Katsuki pulled his fingers free with a wet pop, silencing him. He grabbed Izuku’s jaw, his grip firm enough to bruise. "We can what?" His red eyes glowed faintly in the lamplight. "Negotiate? There is no negotiation. Only obedience."
He released Izuku's face and took a step back. The loss of his heat made Izuku shiver violently. Katsuki’s gaze raked over him, kneeling and exposed, his skin pebbled with goosebumps, his nipples tight and dark against his freckled chest.
"Look at me," Katsuki commanded, his voice low. He didn't move to touch him again. He just stood there, unbuttoning his trousers with deliberate, slow movements. "Look at what your lies have done."
Izuku couldn't look away. His breath came in short, ragged hitches. The sound of the zipper was obscenely loud. Katsuki pushed the dark fabric down his hips, and his cock sprang free, thick and heavy and already leaking at the tip. Izuku’s mouth went dry.
It was massive, just as Katsuki had promised—long and thick, the vein along the underside pulsing. Pre-cum beaded at the slit. The lamplight caught the sheen of it.
"Ten inches of proof," Katsuki said, wrapping a fist around the base. He gave himself a slow, languid stroke, his eyes locked on Izuku’s horrified face. "Proof that your God has abandoned this room. That my want is the only sacrament left."
Izuku whimpered. His own body betrayed him again, a fresh pulse of wetness between his legs. The scent of his own arousal mixed with the beeswax and old paper.
"You see it," Katsuki stated, taking a step closer. The head of his cock nudged against Izuku’s cheek, leaving a hot, sticky smear. "You know what it’s for. Confess."
"N-no," Izuku breathed, trembling. "I won't."
Katsuki’s free hand tangled in his curls again, not yanking, just holding. A threat of force. "You will. You’ll confess how wet your cunt is. You’ll confess how badly you want to be filled with it." He dragged the tip down Izuku’s cheek, over his lips. "Open."
A tear fell. Izuku’s lips parted. The taste of salt and skin and something uniquely Katsuki flooded his mouth as the broad head pressed against his tongue.
"Good," Katsuki murmured, his voice gone rough. "Now keep your eyes on mine. And understand whose corruption you're swallowing."
Katsuki pushed forward without mercy.
The thick head of his cock slid deeper over Izuku’s tongue, hitting the back of his throat. Izuku gagged, a raw, choked sound muffled by flesh. His eyes watered, blurring the sight of Katsuki’s burning red gaze looking down at him.
“That’s it,” Katsuki rasped, his hand tightening in Izuku’s curls. He didn’t stop. He fed him another inch, then another, the stretch brutal and overwhelming. Izuku’s throat convulsed, trying to reject the intrusion, but Katsuki held him firm. “Take it. Swallow around it.”
Izuku couldn’t breathe. Spit dripped from his stretched lips. The taste was salt, skin, and something darker, a faint, bitter tang that might have been sin itself. His mind swam, dazed. The smell of Katsuki’s skin, incense and sweat and male heat, filled his nose. The obscene, wet sounds of his own gagging filled his ears.
“Look at you,” Katsuki groaned, his hips giving a shallow thrust. “Drunk on my cock already. Your god isn’t here. It’s just this.”
And it was. A fresh, hot pulse of wetness dripped from Izuku’s pussy onto the floorboards beneath his knees. The ache between his legs was a deep, throbbing counterpoint to the ache in his throat. He was gagging, tears streaming down his cheeks, and he wanted to stay right there, impaled on this proof of his own corruption.
Katsuki pulled back slowly, letting Izuku gasp a shuddering breath before pushing back in, a fraction deeper. “Your body knows the truth. It’s begging for it.” He used his grip to set a slow, relentless rhythm, each thrust punching a wet, choked sound from Izuku’s throat. “Your pretty cunt is dripping for me. I can smell it.”
Izuku’s hands, which had been clenched at his sides, rose weakly, fluttering near Katsuki’s thighs. Not to push him away. To steady himself.
“Use your tongue,” Katsuki commanded, his voice strained with pleasure. He stilled, buried to the hilt. “Show me you want to keep it.”
Izuku, his vision swimming, obeyed. He pressed his tongue along the heavy vein underneath, laved the shaft as best he could with his mouth so full. A low, approving growl rumbled from Katsuki’s chest.
“Good boy,” he breathed, the blasphemous praise shooting straight to Izuku’s core. “Such a good, sinful boy.” He began to move again, a faster, harder pace that stole any chance of breath. Izuku took it, his body shaking, a willing altar for this desecration.
Katsuki’s free hand came down, fingers skating over Izuku’s flushed, freckled shoulder, down his trembling back, to cup the curve of his ass. “So wet for me everywhere,” he muttered, his thrusts becoming erratic. “Going to fill this pretty mouth. Going to mark you inside.”
A final, deep push, and Katsuki held, his body going rigid. Heat flooded Izuku’s throat, bitter and thick. He swallowed convulsively, instinctively, as Katsuki groaned above him, a sound of pure, victorious pleasure. He kept him there, pinned, until he was spent.
He pulled out slowly. Izuku coughing, strings of spit and cum connecting his lips to Katsuki’s softening cock. He dragged in ragged, sobbing breaths.
Katsuki looked down at him. He ran his thumb over Izuku’s swollen, wet lower lip. “Your first communion,” he said, his voice quiet and terrible. “Now clean the floor. With your tongue. Then we’ll see about the rest of you.”
Izuku obeyed. He lowered his face, his hot cheek pressing against the cold, polished oak floor. The taste of the wood—varnish and dust—filled his mouth first. Then, the salt-bitter tang of his own spend, mixed with Katsuki’s. He squeezed his eyes shut and dragged his tongue in a slow, shameful stripe.
“Louder,” Katsuki said from above him. His shadow covered Izuku completely. “Let me hear your penance.”
Izuku’s next sob vibrated in his throat. He did it again, the wet, lapping sound obscene in the quiet office. The flavors mingled on his tongue: the clean wood, the musky salt, the sour hint of his own shame. He gagged but kept going, his body trembling.
“You kiss the floor with more reverence than you ever kissed the altar,” Katsuki mused, his voice a low rumble. He began to circle again, his polished shoes stopping just beside Izuku’s curled fingers. “Do you feel purified yet?”
“N-no,” Izuku choked out, his face still to the floor. A string of saliva dripped from his lips.
“Good. You shouldn’t.” Katsuki’s foot nudged Izuku’s hip, not a kick, but a demand to move. “On your back. Let me see the rest of the mess you’ve made.”
Izuku shuddered but rolled onto his back, the cold floor a shock against his spine. He kept his arms folded over his small chest, his legs pressed tightly together.
Katsuki tutted. He knelt, his knees framing Izuku’s hips. His red eyes glowed in the lamplight as he pried Izuku’s hands away, pinning them above his head with one strong hand. “This,” he said, his other hand tracing the soft, freckled swell of Izuku’s tits. “This is a lie. But this…” His fingers trailed down, over the frantic flutter of Izuku’s stomach, through the dark curls between his trembling thighs. “This is the truth. Open.”
“Please,” Izuku whispered, his green eyes wide with terror. “Don’t look.”
“I’m not looking. I’m inspecting.” Katsuki applied pressure, and Izuku’s legs fell open with a weak sob. The lamplight fell directly on him, on the slick, swollen folds, the glistening evidence of his unwanted arousal. “See how wet you are? Even now. After what you just did.” He ran a single finger through the wetness, collecting it. “Your body worships this. It always will.”
Izuku turned his head away, fresh tears leaking into his curls. “I hate it.”
“Liar.” Katsuki brought his wet finger to Izuku’s lips, painting them. “You hate that you love it. That’s a different sin.” He leaned down, his breath hot against Izuku’s ear. “I’m going to fuck you on this floor. I’m going to ruin you in the one place you thought was safe. And you’re going to beg me for it before I’m done.”
“I won’t,” Izuku gasped, even as his hips gave a tiny, traitorous jerk.
Katsuki’s smile was a sharp, cruel thing. He released Izuku’s wrists and sat back on his heels, unbuttoning his shirt the rest of the way. The lamplight caught the hard planes of his chest, the demonic sigil that had begun to bloom like a bruise over his heart. “You have two choices. You can lie there and take it. Or you can get on your knees and beg for it like a proper sinner. Which one preserves more of your dignity, Izuku?”
Izuku pushed himself up on his elbows, his body aching. The cold air pebbled his skin. He looked from Katsuki’s face to his cock, already hardening again against his thigh, thick and relentless. The smell of their sex hung in the air, sacred and profane. His voice was a broken thing. “What… what do you want me to say?”
“The truth.” Katsuki’s hand wrapped around himself, stroking slowly. “Tell me you want my cock in your cunt. Tell me you need it.”
Izuku’s mouth worked soundlessly. He swallowed, his throat sore. The words were ashes, but he forced them out. “I… I want it.”
“Louder.”
“I want your cock,” Izuku whispered, the confession tearing something inside him. A fresh wave of wetness seeped from him, betraying him utterly. “Please.”
“Please, what?”
Izuku squeezed his eyes shut. “Please, Father… put it in me.”
“Please, Father… put it in me,” Izuku whispered, the words still hanging in the air like incense.
Katsuki’s smile was a blade. He leaned over, his shadow swallowing Izuku whole. His hand wrapped around the base of his cock, thick and glistening, and he brought it down. The heavy, hot weight of it slapped against Izuku’s bare, freckled chest, a wet, obscene sound in the quiet office.
“Say it properly,” Katsuki commanded, his voice low. He dragged the head through the valley between Izuku’s small tits, leaving a slick trail. “The crude words. The true words. I want to hear the filth in your mouth.”
Izuku flinched at the contact, the heat of him branding his skin. “I… I want…”
“I want your cock,” Katsuki supplied, pressing the tip against Izuku’s puffy nipple, making him gasp. “In my pussy. Say it.”
Tears blurred Izuku’s vision. The shame was a live wire in his gut. But beneath it, a deeper, terrifying ache throbbed between his legs, answering the pressure on his chest. His mouth opened. “I want your cock.”
“Where?”
“In my…” The word choked him. It was a confession, a surrender, a truth he’d never let himself think. “In my pussy.”
Katsuki rewarded him by sliding his cock upwards, smearing pre-cum over Izuku’s throat. “Again. Louder. Beg for it.”
“Please,” Izuku sobbed, his hips lifting off the cold floor, seeking nothing, seeking everything. “Please, I want your cock in my pussy. I want it. I do.” The realization hit him as he said it, a wave of horrifying clarity. He meant it. His virgin cunt, untouched and secret, was clenching around nothing, aching for that impossible girth. “I want it. God, I want it.”
“God isn’t listening,” Katsuki murmured, his red eyes glowing with infernal light. He positioned himself, the blunt head of his cock nudging through Izuku’s curls, seeking the heat beneath. “But I am. And I’m going to give you exactly what you begged for.”
He pushed. Just an inch. A burning, stretching invasion that stole the air from Izuku’s lungs. Izuku’s back arched, a sharp cry tearing from his throat—not pain, not yet, but the shock of fullness, of being opened.
“So tight,” Katsuki groaned, his composure cracking for a second. He looked down between their bodies, watching himself disappear into the slick, trembling folds. “Look at you. Taking me. Your pretty little cunt is swallowing me whole.”
Izuku couldn’t look. He could only feel. The stretch was immense, a burning pressure that promised to split him apart. He clawed at the floor, his knuckles white. “It’s too much,” he gasped.
“It’s what you asked for,” Katsuki reminded him, his voice gravel. He pulled back almost all the way, then sank in again, another inch deeper. The wet, sliding sound was explicit. “You begged for this fat cock. Now take it.”
He set a slow, brutal pace, each thrust carving a little more space inside him. Izuku’s body shook, adjusting, betraying him with every clench around the invading thickness. A broken, continuous moan spilled from his lips.
Katsuki leaned down, bracing his hands on either side of Izuku’s head. His breath was hot on Izuku’s face. “You feel that? Every inch? That’s my claim. I own this now. This tight, sinful heat.” He drove in deeper, finally sheathing himself completely, his hips flush against Izuku’s ass. “You’re full of me.”
Izuku could only nod, overwhelmed, impaled. The fullness was a kind of madness. The demon above him, inside him, was all he knew. The church, his secret, his fears—all drowned out by the relentless, physical truth of their joining.
“Look at it.” Katsuki’s voice was a guttural command. He braced one hand on Izuku’s hip, the other fisting in his green curls, forcing his head up. “Watch what you’re taking. Watch my cock ruin you.”
Izuku’s tear-filled eyes fluttered open, dragged down to where their bodies joined. The sight stole his breath. Katsuki’s thickness was buried to the hilt inside him, his own slickness making a wet, obscene mess around the base. As Katsuki pulled back, the stretch was a visible, brutal thing—his pussy clinging to the girth, lips flushed and swollen, stretched taut around the retreating shaft.
“See how greedy you are?” Katsuki growled, pulling almost all the way out until just the head remained, his cock glistening under the lamplight. Izuku’s entrance pulsed around the intrusion, empty and aching. “Beg for it back.”
Izuku shook his head, a weak denial. The emptiness was worse than the fullness, a hollow need that screamed. His hips lifted, seeking.
“Say it.” Katsuki snapped his hips forward, a shallow, punishing thrust that made Izuku cry out. Then he withdrew again, hovering. “You want this fat cock splitting you open? Beg.”
The words were a dam breaking. “Please,” Izuku sobbed, his hands scrabbling at Katsuki’s thighs. “Please, put it back. I need it. I need it inside, please—”
“Need what?” Katsuki drove in halfway, making Izuku arch, then stopped. “Use the words. Your words.”
“My pussy,” Izuku gasped, the crude term a fire in his mouth. “I need your cock in my pussy. Please, Father, fuck me. I want it. I want to feel it.”
Katsuki seated himself fully with a brutal snap of his hips, punching a ragged scream from Izuku’s throat. “You want this?” He set a hard, driving rhythm, each thrust jolting Izuku’s body across the polished floor. The slap of skin echoed off the bookshelves. “This is what you begged for.”
Izuku could only nod, his mind fragmenting. Every nerve was alight, the burning stretch morphing into a deep, throbbing pleasure that coiled low in his gut. His own moans filled the room, high and desperate. “Harder—!”
The plea seemed to unleash something. Katsuki’s red eyes flashed. He hauled Izuku’s hips up, angling him deeper, and fucked into him with a savage, relentless pace. The desk lamp rattled with each impact.
“Mine,” Katsuki snarled, his demonic conviction absolute. He leaned down, his mouth against Izuku’s ear. “This cunt is consecrated to me. You come on my cock, or you don’t come at all. Understand?”
Izuku understood nothing but the building pressure, the delicious friction, the terrifying rightness of being so completely claimed. His orgasm gathered, swift and inevitable, a wave about to crash. “I’m— I can’t—”
“You can.” Katsuki’s hand slid between them, his thumb finding Izuku’s enlarged clit. A single, rough circle. “Come for me, sinner.”
Izuku’s orgasm tore through him with a violence that turned his vision white. Katsuki’s thumb on his clit was the final spark, and his body seized, a raw, guttural scream ripping from his throat as his cunt clenched in a frantic, rhythmic pulse around the thick cock impaling him. Then it happened—a hot, sudden flood, a release so profound it wasn’t just a climax but an eruption. Liquid gushed from him, soaking Katsuki’s thighs, his balls, the floor beneath them with a sound like a sigh. Izuku squirted, his body convulsing through wave after wave of it, a desperate, humiliating fountain.
Katsuki’s thrusts stuttered. The demon’s composure shattered at the sensation of being bathed in the boy’s release. “Fuck,” he snarled, his red eyes wide with a kind of ravenous awe. He watched the translucent fluid spill, his hips jerking erratically. The sight of Izuku coming apart so completely, so messily, was too much. His own control snapped. With a final, deep grind, he pulled his cock from the slick, spasming heat and stroked himself twice, thick ropes of cum painting stripes across Izuku’s freckled cheeks, his swollen lips, his closed eyelids.
Silence, save for their ragged breathing. The smell of sex and wax and salt filled the office. Izuku lay ruined, trembling, his own release cooling on his stomach and thighs, Katsuki’s spend hot on his face.
Katsuki looked down at him, his chest heaving. He swiped a thumb through the mess on Izuku’s cheekbone, then brought it to his own mouth, tasting. His gaze was dark, thoughtful. “You ruined the floor,” he said, his voice hoarse. “Again.”
Izuku couldn’t speak. He turned his head away, a tear cutting through the semen.
“Look at me.” Katsuki’s hand gripped his chin, forcing it back. His thumb smeared the sticky warmth across Izuku’s lips. “You begged for my cock, and you came like a whore. You flooded this sacred office. What does that make you?”
“A sinner,” Izuku whispered, the words automatic, hollow.
“My sinner,” Katsuki corrected, his voice dropping to a possessive rumble. He released Izuku’s face and stood, his shadow falling over the boy’s shivering form. He looked at the puddle on the polished wood, then at Izuku’s spent body. “Clean it. With your tongue. Then get dressed. The confessionals won’t polish themselves.”
Izuku pushed himself up on shaking arms. The cold air hit his wet skin, raising goosebumps. He didn’t look at Katsuki. He bent, his green curls brushing the floor, and lapped at the mixed fluids, the taste of himself and the priest salt-bitter on his tongue. Each pass of his tongue was a prayer to nothing.
Katsuki watched, buttoning his shirt with deliberate slowness, tucking himself away. The demonic glow in his eyes had banked to embers, but the satisfaction there was absolute. “Sunday,” he said, as Izuku found his discarded clothes with trembling hands. “The bell tower. Before vespers. You’ll meet me.”
It wasn’t a question. Izuku pulled his binder on, the familiar constriction now feeling like a cage of his own making. He nodded, unable to lift his eyes from the spot on the floor he’d just cleaned, now shining under the lamplight.
“Good,” Katsuki said. He picked up his clerical collar from the desk, running a finger along its white band. “Our penance continues. Now get out of my sight.”