Izuku's hands trembled as he carried the basin of warm water into Katsuki's room, steam curling up into the heavy afternoon air. The old man was propped against the headboard, his robe hanging loose around his shoulders, those crimson eyes tracking Izuku's every movement like a hawk watching prey.
"Took you long enough," Katsuki grunted, but there was no heat in it. Just the familiar gruffness that Izuku had learned to read as something softer underneath.
"I had to get the temperature right." Izuku set the basin on the nightstand, his voice coming out thinner than he wanted. "The doctor said you shouldn't strain yourself, so I need to—"
"I know what a sponge bath is, boy. I'm old, not senile."
Izuku's cheeks burned. He busied himself with the cloth, dipping it into the water, watching the fabric darken as it soaked up the heat. This is fine. This is just helping. This is what a good grandson does. The words felt hollow even inside his own skull, a prayer that wouldn't be answered.
"Well?" Katsuki's voice cut through the silence. "You gonna stand there all day or you gonna get to work?"
"Right. Sorry." Izuku turned, cloth in hand, and the sight of Katsuki shrugging off the robe stole the breath from his
The old man's body was a map of hard labor and years—broad shoulders dense with muscle, chest dusted with silver and ash-blond hair, the thick column of his throat, the way his skin gleamed in the late afternoon light filtering through the dusty window. Izuku's mouth went dry. His fingers tightened around the cloth until his knuckles went white.
"You okay there, kid?" Katsuki's voice was lower now, rougher, and when Izuku met his eyes there was something knowing in that crimson gaze. Something that made his stomach flip.
"Fine. I'm fine." Izuku stepped closer, his heart hammering so loud he was sure the old man could hear it. He pressed the warm cloth to Katsuki's shoulder, running it along the swell of his deltoid, feeling the heat of his skin through the fabric.
Katsuki didn't say anything. He just watched, his breathing slow and even, his chest rising and falling beneath Izuku's trembling hands. The cloth traced down his arm, over the curve of his bicep, across his forearm, until Izuku was holding his calloused hand, washing each finger with a care that bordered on reverence.
"You're being real thorough," Katsuki muttered, and there was something almost teasing in his tone.
"I want to do it right." Izuku didn't look up. He couldn't. If he looked up, he'd see those eyes again, and he'd lose whatever fragile composure he was clinging to. He moved to the other side, pressing the cloth to Katsuki's chest, dragging it slowly across the firm muscle, over his nipple, feeling it pebble beneath the warmth.
The silence stretched between them, thick and heavy, broken only by the soft sound of water dripping back into the basin. Izuku's hand moved lower, tracing the hard plane of Katsuki's stomach, following the trail of hair that disappeared beneath the loose fabric pooled at his hips.
"Almost done with the top half," Izuku whispered, more to himself than to Katsuki.
"You haven't even touched the bottom half yet."
Izuku's throat closed. He forced himself to breathe, to rinse the cloth in the basin, to wring it out. The water was cooler now. He didn't care. His entire body was on fire, every nerve ending screaming at him as he knelt beside the bed, his hand hovering over the knot of Katsuki's robe at his hip.
"I need you to—" Izuku's voice cracked. He swallowed hard. "I need to wash your legs. And your..." He couldn't finish the sentence. The word hung between them, unspoken, unbearable.
"My cock." Katsuki said it like it was nothing. Like it was weather. Like he wasn't watching Izuku's face go scarlet, watching his hands shake, watching the desperate hunger that Izuku couldn't hide bleeding through every pore.
Izuku nodded, a tiny, jerky motion. His fingers found the knot, fumbled with it, and the robe fell open.
The robe fell open and Izuku's breath stopped. There it was. Katsuki's cock lay soft against his thigh, thick and heavy, the uncut foreskin bunched at the tip like a hood over something waiting. Even flaccid it was massive—ten inches of flesh that seemed impossible, a weight that made Izuku's mouth water and his cunt clench in the same breath. His hand trembled, the cloth dripping onto the floorboards. He couldn't look away.
"You gonna wash my legs or just stare at 'em?" Katsuki's voice was rough, but there was a brittleness underneath, something almost nervous.
Izuku's face burned. He dropped his gaze to Katsuki's thigh, pressing the warm cloth against the thick muscle, dragging it down toward his knee. But his eyes kept drifting back. Back to that cock. Back to the way it rested there, soft and huge, a promise he couldn't stop imagining. Don't look. Don't look. You're cleaning him, that's all. His hand moved lower, washing Katsuki's calf, his ankle, his foot. Each stroke brought him closer to where he needed to be.
"Almost done with the legs," Izuku whispered, his voice cracking. He moved to the other side, pressing the cloth to Katsuki's thigh, working his way down. But his eyes—his eyes never really left that cock. It was right there, inches from his face now that he was kneeling beside the bed. He could smell it. Musk and salt and something deeper, something that made his head spin.
Katsuki's breathing changed. A sharp inhale. Izuku's gaze flicked up and he saw it—a twitch. A subtle shift in the heavy flesh. The foreskin began to retract, the head emerging like a slow sunrise, pink and dark and slick. Izuku watched, frozen, as Katsuki's cock began to harden. It rose slowly, thickening, lengthening, the shaft stretching up until it stood fully erect, jutting out from the nest of ash-blond pubic hair, ten inches of thick, veined, uncut meat that Izuku could almost taste.
He swallowed hard. His hand had stopped moving on Katsuki's leg. The cloth hung limp in his fingers.
"Fuck," Katsuki muttered, his voice strained. "Sorry. I didn't mean to—" He shifted, reaching down as if to cover himself. "I can take care of the rest, kid. Just leave the basin."
Izuku didn't move. His hand tightened on the cloth. He stared at that cock, at the way it curved slightly upward, at the bead of moisture gathering at the tip, at the thick vein pulsing along the side. I should leave. I should leave right now. This is so wrong. He's my grandfather. But his body didn't listen. His hand moved, the cloth pressing against the base of Katsuki's shaft, dragging upward in a slow, deliberate stroke.
Katsuki's breath caught. "Izuku—"
He didn't stop. The cloth slid over the hot, rigid flesh, following the line of the shaft, up over the head where the foreskin had fully retracted, then back down. Katsuki's hips twitched, a soft grunt escaping his throat. Izuku's entire world narrowed to the feel of that cock through the wet fabric, the heat of it, the way it jumped under his touch.
"You don't have to—" Katsuki started, but his voice cracked and died.
The cloth slipped from Izuku's fingers. It landed on Katsuki's thigh with a wet slap. And then Izuku's bare hand was wrapped around his grandfather's cock, fingers closing around the thick shaft, feeling every ridge and vein against his palm. It was so hot. So impossibly thick. His hand barely fit around it.
"Izuku." Katsuki's voice was a groan, a warning, a prayer. He didn't push Izuku away. He didn't tell him to stop.
Izuku's hand began to move. Slow, tentative at first, the way he'd learned from watching porn in the dark of his bedroom, from touching himself while thinking about this exact moment. His palm dragged up the shaft, over the slick head, his thumb spreading the wetness there, then back down. Katsuki's cock was heavy in his grip, and the sound it made—a wet, sticky sound—filled the room.
"Fuck, kid," Katsuki breathed, his head falling back against the headboard. His hands gripped the sheets, knuckles white. "You don't know what you're doing."
But Izuku did. His hand tightened, twisting on the upstroke, finding a rhythm that made Katsuki's hips buck. The old man's cock was slick with precum now, and each stroke was easier, smoother, the wet sounds growing louder. Izuku's other hand came up to cup the heavy balls hanging beneath, rolling them gently in his palm.
Katsuki's thighs trembled. He let out a sound—low, broken, almost a sob—and his head turned, crimson eyes finding Izuku's green ones. There was shame there, and heat, and something desperate. "You're gonna make me—" He didn't finish. His hips thrust up into Izuku's fist, once, twice, and then his whole body tensed.
Izuku felt it. The cock in his hand swelled, pulsed, and then hot ropes of cum shot across his fingers, splattering his wrist, dripping onto Katsuki's stomach. He didn't stop. He kept stroking, milking every drop, watching Katsuki's face contort with pleasure, watching the old man come undone beneath his hands.
When it was over, Izuku's hand was slick with release. He stared at it—at the evidence of what he'd done—and then at Katsuki, whose chest was heaving, whose eyes were wide and stunned and full of something that looked almost like fear.
Izuku's hand stayed wrapped around Katsuki's cock, feeling it pulse against his palm even after the last drop of cum had spilled across his fingers. The shaft was still hard, still throbbing, still aching with a hunger that hadn't been satisfied. Izuku's thumb found the head, smearing the wetness there in slow, deliberate circles, watching the way Katsuki's breath hitched with each touch.
"You're still hard, Papa Kats." Izuku's voice came out soft, almost wondering. He looked up through his lashes, green eyes meeting crimson. "Do you need me to make you cum again?"
Katsuki's jaw tightened. His hands were still gripping the sheets, his chest still heaving. "Kid, that's—" He swallowed hard. "That's not—" He couldn't finish. His cock twitched in Izuku's grip, leaking a fresh bead of precum against his thumb.
"You do, don't you?" Izuku's hand began to move again, slow and teasing, dragging his palm up the slick shaft. "You need cum more. I can feel it."
"Izuku." Katsuki's voice was rough, almost pleading. "This is wrong. You're my—" He stopped. The word hung between them like a wall neither of them wanted to build.
"I know." Izuku kept stroking, his fingers tightening around the thick shaft, feeling every ridge and vein. "I know it's wrong. But I don't care." His thumb circled the head again, spreading the wetness. "I want to make you feel good. I want to watch you fall apart again."
Katsuki's cock throbbed in Izuku's grip, a pulse that traveled up the shaft and into Izuku's palm like a heartbeat. The old man's breath came in ragged gasps, his chest heaving, his crimson eyes fixed on Izuku with something between hunger and horror.
"You shouldn't—" Katsuki's voice cracked. He swallowed hard, his throat bobbing. "You shouldn't want to do this. Not with an old man like me. Not with your—" He couldn't finish the word. It sat between them, heavy and wrong.
Izuku's hand kept moving, slow and deliberate, stroking the slick shaft. "I do want to."
"You're eighteen." Katsuki's hands were still gripping the sheets, white-knuckled. "You should be out there with boys your age. Not stuck here with some broken-down bastard who can barely walk."
"I don't want boys my age." Izuku's voice came out steady, surprising himself.
Katsuki let out a sound—half laugh, half groan. "Fuck, kid. We shouldn't be doing this.”
Izuku's thumb traced the ridge of Katsuki's cockhead, spreading the wetness there. "I've been thinking about this since the moment I saw you."
Katsuki's jaw tightened. His eyes searched Izuku's face, looking for something—doubt, hesitation, a way out. He didn't find it. "Do you even have experience doing this, kid?" The question came out rough, almost reluctant. "With anyone?"
Izuku's hand paused. Heat flooded his cheeks. "No," he admitted, his voice small. "I haven't. Not with anyone."
Katsuki's expression shifted—surprise, then something softer, almost tender. "Then you don't know what you're doing."
"I know what I want." Izuku's hand tightened on Katsuki's cock, feeling the heat of it, the weight. "I want to do this to you. I want to make you feel good."
Katsuki stared at him for a long moment. Then he let out a breath, his shoulders sagging slightly. “You're gonna fucking wreck me," Katsuki breathed, the words punched out of him.
Izuku didn't answer. He leaned forward, his lips brushing against the flushed purple head of Katsuki's cock. The taste hit him—salt and musk and something darker, something that made his head spin. He pressed a soft kiss to the tip, feeling it twitch against his mouth.
Katsuki's breath caught. "Izuku—"
Izuku's lips parted. He took the head into his mouth, suckling gently, his tongue tracing the ridge where the foreskin had retracted. The taste flooded his senses, warm and thick and intoxicating. He heard Katsuki's head thud back against the headboard, a low groan escaping his throat.
Katsuki's fingers tangled in Izuku's hair, thick and rough, gripping the green curls at the root. "Shit," he breathed, his hips twitching as Izuku's tongue worked the head of his cock. "You don't know what the hell you're doing, do you?"
Izuku didn't pull back. He sealed his mouth around the fat head of his cock, his tongue working the sensitive ridge in slow, deliberate circles. His eyes stayed locked on Katsuki's, hungry and unguarded, lips slick and stretched as he suckled.
Something broke in Katsuki's gaze. His hand tightened in Izuku's hair, and he pushed, a pressure that said *like this*. He guided Izuku's head down, forcing his cock deeper into that wet, eager mouth. Izuku's throat constricted, a reflexive gag that made Katsuki's whole body tense.
"Fuck," Katsuki groaned, his head falling back. "You're just a kid. Eighteen years old and you're down on your knees for your goddamn grandfather." His voice cracked on the word, but his hand didn't loosen. "This is so fucked up."
Izuku's response was a muffled hum, the vibration making Katsuki's hips buck. He kept moving, letting the old man guide him, letting that calloused hand set the rhythm. Up, then down. Up, then down. Each stroke pushed him deeper.
"You like it, don't you?" Katsuki's voice was ragged, almost accusatory. "You like being down there, choking on an old man's cock."
Izuku's eyes fluttered up, green meeting crimson, and he didn't look away. His tongue traced the thick vein on the underside as he slid back up, tasting salt and precum.
"Fucking hell, kid." Katsuki's grip tightened, his hips starting to move in counterpoint to his hand, fucking into Izuku's mouth with shallow thrusts. "Twenty years. It's been twenty years since anyone—" He cut off with a groan, his cock twitching against Izuku's tongue. "And it's my grandson. My own fucking blood."
Izuku's hands came up, gripping Katsuki's thighs, feeling the coarse hair and hard muscle beneath his palms. He wanted more. He wanted all of it. He pulled back, just an inch, and Katsuki made a sound of protest that died when Izuku opened his throat and took the whole length in one desperate swallow.
The world went dark. His throat convulsed, gagging, choking, spit spilling down his chin and pooling in his collar. Tears streamed from his eyes, hot and humiliating and electric. But he didn't pull away. He stayed there, impaled on his grandfather's cock, feeling the pulse of it against his gagging throat.
Katsuki froze. "Izuku—"
Izuku's nails dug into his thighs. He didn't move. He waited. He wanted it. The punishment of it, the stretch, the burn, the way his body fought something his soul craved. He wanted to be used.
"You're gonna kill me," Katsuki breathed, but his hand was already moving again, gripping Izuku's curls and forcing his head down, holding him there until Izuku's throat spasmed around the thick shaft. Then he pulled back, letting Izuku gasp, only to push in again, harder this time.
Izuku choked and swallowed, his body learning the rhythm, his throat opening to accept what he couldn't refuse. The sound of it—wet and obscene and desperate—filled the room.
"You're just a kid," Katsuki repeated, his voice broken and hungry. "Eighteen years old, never been touched, and you're taking your grandpa's cock down your throat like you were made for it."
Izuku's moan was muffled, lost in the flesh filling his mouth. His hands slid up Katsuki's thighs, gripping his hips, pulling him deeper. Tears and spit soaked his face, his neck, his crop top. He didn't care. He wanted to be wrecked.
Katsuki's rhythm grew ragged, his breathing harsh. "That's it. Take it. Take all of it, you desperate little—" He cut off, hips snapping forward, burying himself in Izuku's throat with a sound that was half groan, half sob. "Fuck, I'm gonna—"
But he didn't come. He pulled out instead, letting Izuku gasp and cough, a string of spit connecting his lips to the slick head of Katsuki's cock. Izuku looked up at him, green eyes watery and wrecked, lips swollen and red.
"More," Izuku whispered. His voice was raw, broken. "Please, Papa Kats. More."
Katsuki stared at him for a long moment, chest heaving, cock hard and wet and throbbing in the space between them. Then his hand found Izuku's hair again, and he pushed him back down.
Katsuki's grip tightened in Izuku's hair, and he drove his hips forward with a grunt, burying the full ten inches of his cock down Izuku's throat in one brutal, hungry thrust. Izuku's body seized, his hands flying to Katsuki's thighs as his throat convulsed around the thick shaft, tears streaming from his eyes. The old man didn't stop—he pulled back, letting Izuku gasp for half a breath, then slammed in again, his heavy low-hanging balls slapping against Izuku's chin with a wet sound that filled the room.
"That's it," Katsuki growled, his voice ragged and raw. "Take it. Take every fucking inch, you desperate little slut." He set a brutal rhythm, each thrust punching deeper, using Izuku's throat like it was made for this. "Can't believe I got a grandson who loves choking on old man cock."
Izuku's moan was lost, swallowed by the flesh filling his mouth. His eyes fluttered, half-rolled back, tears and spit soaking his face. His hands gripped Katsuki's thighs, nails digging into the coarse hair and hard muscle, anchoring himself as the old man fucked his throat.
"Look at you," Katsuki breathed, his crimson eyes fixed on Izuku's wrecked face. "Eighteen years old, never been touched, and you're down on your knees, gagging on your own granddaddy's dick." He pulled back, letting Izuku choke and cough, a string of spit connecting his swollen lips to the slick head of Katsuki's cock. "You like that, don't you? Being your grand daddy's little cocksleeve?"
Izuku's answer was a desperate, eager nod, his green eyes watery and hungry. He opened his mouth, tongue out, waiting. The gesture was pure want, pure submission.
Katsuki's jaw tightened. "Fucking hell, kid." He seized Izuku's hair again and shoved his cock back in, deeper this time, holding him there until Izuku's throat spasmed around the shaft. "You wanna be my fuck toy? My personal cocksleeve to get my nut off whenever I want?"
Izuku's throat convulsed around him, a muffled sound of agreement escaping. His hands slid down Katsuki's thighs, gripping his hips, pulling him deeper even as his body fought the intrusion. He wanted this. He wanted to be used, to be wrecked, to be nothing but a hole for his grandfather's pleasure.
Katsuki's rhythm grew violent, his hips snapping forward with desperate, punishing thrusts. The sound of it—wet and obscene, the slap of his balls against Izuku's chin—filled the room like a pulse. "You want to drain your own grandfather's nuts, don't you? Want me to fill your throat with my cum, make you swallow every drop?"
Izuku's nails dug into Katsuki's hips. His only answer was the continuous, eager choking as he took every inch, his throat opening to accept what he couldn't refuse. His body was on fire, his pussy soaking through his shorts, the wet fabric clinging to his skin.
Between thrusts, Izuku's hands fumbled at his waist. He shoved his shorts down, the fabric catching on his hips before he kicked them free. His thong was soaked, the thin fabric transparent with his arousal. He pushed it aside without hesitation, his fingers finding his swollen, slick pussy, and he moaned around Katsuki's cock as he pressed two fingers inside.
Katsuki's eyes dropped, catching the movement. His breath hitched, and his thrusts grew harder, more brutal. "Fuck, look at you. Touching that desperate little cunt while you choke on my cock." He pulled out just enough to speak, his voice a harsh whisper. "You're fucking pathetic. And I love it."
Izuku's fingers worked his pussy, the wet sound joining the obscene chorus. He curled them, searching for that spot, his hips grinding against his own hand as Katsuki's cock filled his mouth. The pleasure was blinding, a hot electric current running from his throat straight to his clit.
Katsuki's grip tightened, and he drove into Izuku's throat with renewed violence, his balls slapping wetly against Izuku's chin with every thrust. "That's it. Finger that little cunt while I fuck your throat. Show me how much of a desperate slut you are for your granddaddy's cock."
Izuku's eyes rolled back. His fingers moved faster, fucking his pussy in rhythm with Katsuki's thrusts, each stroke pushing him closer to the edge. The world narrowed to the feeling of his grandfather's cock in his throat, his own fingers inside his cunt, the heat and the wet and the wrongness that made it so good.
"You're gonna come, aren't you?" Katsuki's voice was broken, almost reverent. "Gonna come on your own fingers while your granddaddy's cock fucks your face." He pulled back, letting Izuku gasp, then slammed in again, holding him there. "Do it. Cum for me. I want to feel you choke on my cock when you do."
The command hit him like a physical blow, and something inside Izuku snapped. His fingers curved hard inside his own soaked cunt, pressing against that spot, and his body seized around them. The orgasm ripped through him from somewhere deep—his throat convulsed around Katsuki's cock, his pussy clenched around his own fingers, and then the world dissolved into white static.
He felt it happen. Felt the release leave his body in a hot, violent gush, felt it soaking his hand, his thigh, the floor beneath him. But his eyes were closed, tears and spit and sweat blurring his vision, and he didn't see what his body had done until he heard Katsuki's sharp inhale.
"What the fuck."
Izuku's eyes fluttered open. Katsuki was staring down at him, crimson eyes wide, his cock still buried deep in Izuku's throat. But his gaze was fixed somewhere beyond Izuku's head, tracking the arc of something across the room.
Izuku pulled back, gasping, his lips leaving Katsuki's cock with a wet sound. He turned his head, and his own breath caught.
A stream of clear fluid lay across the floor—a thin, glistening trail that started at his own spread legs and ended three feet away, splattered against the leg of the dresser. Like a broken firehose. Like he'd fucking gushed.
"You squirted," Katsuki said, his voice hoarse, disbelieving. "You—you squirted across the goddamn room."
The words hit Izuku like a shock. His face burned, but between his thighs, his pussy was still clenching, still leaking, still desperately empty. He looked up at Katsuki, green eyes watery and wrecked, his lips swollen and shining with spit and precum.
"I'm sorry," he whispered, because what else could he say?
Katsuki didn't answer. His hand was already moving, wrapping around the base of his cock, stroking once, twice—his jaw tight, his breathing ragged. "Open your mouth."
Izuku obeyed without hesitation. He opened wide, tongue out, eyes fixed on Katsuki's face.
Katsuki groaned, a sound that came from somewhere deep in his chest, and he shoved his cock back into Izuku's waiting mouth. But this time he didn't thrust. He held himself there, buried to the hilt, his hips grinding as his body tensed. "Take it. Take it all, you desperate little—"
Hot liquid flooded Izuku's throat. Thick and bitter and so much of it, rope after rope of cum sliding down his esophagus, filling his mouth faster than he could swallow. He choked, gagged, but he didn't pull away. He swallowed, and swallowed, and swallowed, feeling his grandfather's cock pulse against his tongue with each spurt.
Then Katsuki pulled out. Fast. Rough. His hand jerked once, twice more, and the next ropes landed across Izuku's face—across his lips, his cheeks, his nose, his closed eyes. He felt it dripping down his chin, pooling in the hollow of his collarbone, warm and heavy and obscene.
"Fuck," Katsuki breathed, chest heaving, staring down at him.
Izuku didn't open his eyes. He didn't move. He just sat there, covered in it, feeling it cool against his flushed skin. Then slowly, deliberately, he lifted his tongue and licked the cum from his own lips. The taste was bitter, musky, salty—like Katsuki's skin, like his sweat, like the smell of him after a long day's work. It was the most perfect thing Izuku had ever tasted.
He opened his eyes, looked up at Katsuki, and leaned forward. His tongue traced the slick shaft of his grandfather's cock, cleaning it, tasting Katsuki more. He licked every inch, from the base to the tip, his eyes never leaving Katsuki's stunned crimson gaze. He lapped at the head, collecting the last drops, then pulled back and licked his own lips again.
His fingers found the cum on his cheek, scooping it up, bringing it to his mouth. He sucked his fingers clean, one by one, tasting the proof of what they'd done. He did the same for the cum on his chin, on his neck, licking his own palm clean like a cat savoring the last of a meal.
Katsuki watched. Silent. Frozen. His cock softening between them, glistening wet with saliva and cum and precum.
Izuku's hand came up, wiping a smear of cum from his eyebrow, and he licked it off his thumb. Then he smiled. Small. Shy. Wrecked. "Thank you, Papa Kats."
The words hung in the air, and something shifted.
Katsuki's eyes changed. The heat faded, replaced by something colder. He looked down at Izuku—at the cum drying on his face, at his pussy still wet and exposed, at the thin trail of squirt still glistening across the floorboards—and his jaw tightened.
"Get cleaned up," he said, and his voice was flat. Dead. "I need—" He stopped. Ran a hand over his face. "Fuck."
Izuku's smile faltered. The warmth in his chest curdled, replaced by a cold, creeping dread. He watched Katsuki turn away, watched his grandfather's broad back tense as he reached for his discarded robe.
"Papa Kats—"
"Don't." Katsuki pulled the robe on, not bothering to tie it. He stood there, chest still bare, his softening cock still visible. But he wouldn't meet Izuku's eyes. "Just—don't. Not right now."
The silence stretched. Izuku sat on the bed, still half naked, still covered in cum, still trembling. His pussy was sore. His throat ached. His face was sticky and wet.
And all he could feel was the weight of what they'd done pressing down on his chest like a stone. They just crossed a line that should never be crossed.