The shower was a sanctuary of white noise and too-hot water, the spray pounding against Izuku’s shoulders as he braced his hands against the tile. He’d woken alone, Shoto still deeply asleep beside him, the memory of Katsuki’s weight and words a physical imprint. He needed to wash it all away, or maybe seal it in. He wasn’t sure.

The bathroom door clicked open, a subtle sound drowned by the shower’s roar. Izuku didn’t hear it. He only felt the shift in the air, a cool draft cutting through the steam, and then the glass door slid aside.

Katsuki stood there, completely naked, his big body a stark silhouette against the brighter light of the bathroom. Water droplets beaded instantly on his shoulders and chest. He didn’t speak. Just stepped into the tub and pulled the door closed behind him.

Izuku jumped, his heart slamming against his ribs. “Kacchan—!”

“Quiet.” Katsuki’s voice was a low rumble, almost swallowed by the water. He reached past Izuku, his arm brushing his nephew’s slick side, and adjusted the knob. The scalding heat softened to something warm, enveloping. “You’ll burn your skin off, nerd.”

He took the bar of soap from the caddy. His movements were slow, deliberate. He worked it into a lather between his large, rough palms. “Turn around.”

Izuku hesitated, his green eyes wide, droplets clinging to his lashes. But he turned, presenting his back to his uncle. He expected roughness. Demand.

Katsuki’s soapy hands settled on his shoulders. They didn’t grab. They kneaded. Strong, sure thumbs pressed into the tense muscle along Izuku’s spine, working down in slow, circular motions. Izuku’s head dropped forward, a shaky exhale leaving him. The heat of Katsuki’s body radiated against his back, not quite touching except for those hands.

“They’re still out cold,” Katsuki said, his voice close to Izuku’s ear. He smoothed lather over Izuku’s shoulder blades, down the dip of his waist. “Your prince. My idiot. Drugged on holiday cheer and cheap wine.”

“This is…” Izuku began, but the words dissolved as Katsuki’s hands soaped the curve of his ass, a firm, thorough sweep that was clinical and intimate all at once.

“What? Dangerous?” Katsuki’s hands moved to his thighs, scrubbing gently. “Reckless?”

“Different,” Izuku breathed.

Katsuki was silent for a long moment, his hands stilling. Then he guided Izuku to turn back around under the spray. Water sluiced the soap away, revealing the constellations of freckles across his chest and shoulders. Katsuki’s crimson eyes tracked the paths of the water. He looked at Izuku’s face, not his body.

“Yeah,” Katsuki finally said, the word raw. He cupped Izuku’s jaw, his thumb swiping a drop from his cheekbone. “It is.”

He leaned in. The kiss wasn’t a claim. It was a question. Slow. The warm slide of lips, the shared breath of steam. Izuku melted into it, his own hands coming up to rest on Katsuki’s wet chest. He could feel the frantic beat of his uncle’s heart under his palm.

Katsuki broke the kiss, just barely. His forehead rested against Izuku’s. “Let me,” he murmured, and it wasn’t clear what he meant until he was reaching for the shampoo.

Katsuki poured shampoo into his palm, the scent of cedar and mint cutting through the steam. His fingers, thick and rough, slid into Izuku’s wet curls. “Look at me,” he murmured, and Izuku tilted his head back, water catching in his open mouth.

“You love this hair,” Izuku whispered, his voice thin.

“Shut up,” Katsuki said, but it was soft. His hands began to work, massaging the soap into Izuku’s scalp with a slow, circular pressure that made Izuku’s knees go weak. He wasn’t washing. He was kneading. Unknotting. His thumbs pressed deep behind Izuku’s ears, and a broken sound, half-moan, half-sigh, slipped out.

“See?” Katsuki’s breath was hot against his temple. “Told you you were tense.”

Izuku’s hands came up, fingers splaying across Katsuki’s slick pectorals, clinging. He felt the solid, unyielding reality of his uncle’s chest, the frantic heartbeat under his palms. “Kacchan.”

“Yeah.” Katsuki guided him back under the spray. Water cascaded over Izuku’s head, over Katsuki’s hands, rinsing the suds away in white rivers. Izuku kept his eyes closed, face upturned, trusting himself completely to those hands.

When the water ran clear, Katsuki cupped his jaw again. He leaned in and kissed him. It was slow. Deep. A lazy exploration of tongue and heat that tasted of mint and something uniquely Katsuki. Izuku melted into it, his body curving forward until their chests slid together, wet skin on wet skin.

They broke for air, foreheads touching. “They could wake up,” Izuku breathed, the words a vibration between their lips.

“They won’t.” Katsuki kissed the corner of his mouth, then the hinge of his jaw. His hands slid down Izuku’s back, possessive and steadying. “Not yet.”

He kissed him again, deeper this time, one hand tangling back into his clean curls, holding him in place. Izuku whimpered into his mouth, his own hands roaming over the hard planes of Katsuki’s shoulders, his back, learning the shape of him without hurry. This wasn’t frantic. It was a slow, devouring ache.

Katsuki pulled back just enough to speak, his lips brushing Izuku’s with each word. “Been wanting to do that for years. Just this. In a shower. Getting you clean.”

Izuku’s breath hitched. “I’m not clean.”

“You are right now.” Katsuki’s voice was a low rasp. He trailed his mouth down Izuku’s throat, licking the water from the hollow. “For this minute, you’re just mine.”

Izuku clung tighter, his face pressed into the damp skin of Katsuki’s neck. The water beat down on them, a warm, private cocoon. He didn’t want to let go. He wanted this stolen, steamy forever, where the only sounds were their breathing and the spray and the quiet, desperate truth of their mouths.

Izuku’s mouth broke from Katsuki’s, his breath coming in ragged puffs against his uncle’s wet skin. The steam felt thick enough to choke on. “Back in my dorm,” he whispered, the words stumbling out. “Before I came home. I… I thought about this.”

Katsuki stilled, his hands resting on the dip of Izuku’s waist. His thumbs stroked idle, possessive circles. “What about it?”

“You. In the shower with me.” Izuku’s voice was a thin, shameful thread. He couldn’t look up. “I’d get in after practice, all sore, and I’d… I’d imagine you walking in. Just like you did. Turning the water down. Washing my hair.”

“Yeah?” Katsuki’s voice was low, a vibration Izuku felt in his own chest. He hooked a finger under Izuku’s chin, tilting his face up. The spray hit the side of Izuku’s neck, a warm, relentless pulse. “What else did you imagine, nerd?”

Izuku’s throat worked. He felt his small, budding chest tighten, his puffy nipples pebbling hard against Katsuki’s sternum. “Your hands. Soap. Everywhere. Slower than you’re doing now. Taking forever.”

Katsuki’s crimson eyes darkened. He didn’t speak. Just listened, his gaze fixed on Izuku’s mouth.

“And you’d get hard,” Izuku rushed on, his own hand sliding down Katsuki’s slick stomach, his fingers trembling as they brushed the thick, coarse hair at the base of his cock. He felt it, heavy and half-hard against his wrist. “I’d imagine feeling it against me. Here.” He guided Katsuki’s hips forward, until the hot, thick weight of his uncle’s length settled against his own lower belly. A shudder ripped through him.

“Keep talking,” Katsuki growled. He leaned in, biting gently at Izuku’s bottom lip.

“You’d lift me,” Izuku gasped into the bite. “Press me against the tile. And you’d just… look at me. For like, a full minute. Just looking. Before you did anything else.”

“Fuck.” Katsuki’s head dropped, his forehead pressing into Izuku’s shoulder. His breath was hot and ragged. “You think about that? Me just… looking at you?”

“Yes.” Izuku’s fingers traced the thick vein on the underside of Katsuki’s cock, feeling it jump under his touch. It was fully hard now, a heavy, girthy heat against his palm. “I’d get so wet thinking about it. I’d have to touch myself. Every time.”

Katsuki’s hand slid from his waist, around to the curve of his ass. His fingers dipped lower, through the cleft, until the rough pad of his middle finger found the slick, hairless seam of Izuku’s pussy. He didn’t push inside. Just stroked, a slow, maddening pass over his nephew’s clit. Izuku’s knees buckled, a sharp cry tearing from his throat.

“You’re wet now,” Katsuki murmured, his voice thick with awe. He brought his finger back up, holding it between their faces. It glistened in the dim, honeyed light. “See?”

Izuku whimpered, his hips pushing forward helplessly, seeking the pressure of Katsuki’s body. “It’s only ever like this for you.”

That did it. Katsuki’s control snapped, quiet and absolute. He turned Izuku around, his big body caging him in, one arm banding across his chest to pull him flush against him. The hard length of his cock settled into the cleft of Izuku’s ass, a blunt, insistent pressure. His other hand smoothed down Izuku’s stomach and back to his soaked cunt.

“Show me,” Katsuki breathed into his ear, his teeth grazing the lobe. “Show me how you touched yourself thinking about me.”

Izuku’s hand trembled as he covered Katsuki’s, guiding his uncle’s fingers. He spread his own slick over his clit, making small, tight circles. His head fell back against Katsuki’s shoulder, his eyes squeezing shut. “Like this.”

“Yeah.” Katsuki watched, his breath coming in harsh gusts against Izuku’s neck. He took over, his movements mimicking Izuku’s but firmer, more deliberate. “And then what?”

“Then I’d… I’d imagine you fucking me.” The words were a broken whisper. “Right there in the shower. The water getting in my mouth. You holding me up. Making me squirt all over the wall.”

Katsuki’s finger pushed inside him, just one, a slow, stretching invasion. Izuku cried out, his back arching. He was so open, so ready. He clenched around the intrusion, a fresh gush of wetness coating Katsuki’s hand.

“You wanna come?” Katsuki’s voice was ragged. He added a second finger, the stretch burning sweetly. “From my hand? Like you did in your little dorm fantasy?”

“Yes,” Izuku sobbed, his hips rocking back onto Katsuki’s fingers, forward against his circling thumb. “Please, Kacchan. Please.”

“Then come.” Katsuki’s mouth found the junction of his neck and shoulder, sucking a bruise into the freckled skin as his fingers curled, finding the perfect spot inside him. “Soak my hand. Let me feel it.”

It was too much. The confession, the fingers, the teeth on his skin, the water pounding down. Izuku shattered. A raw, guttural sound was torn from his throat as his body convulsed, his cunt clenching rhythmically around Katsuki’s fingers. Liquid heat gushed out of him, a fountain of release that mixed with the shower spray, dripping down his thighs and Katsuki’s wrist. He shook through it, helpless, held upright only by his uncle’s arm across his chest.

As the tremors subsided, Katsuki slowly withdrew his fingers. He brought his soaked hand to his mouth, his crimson eyes locked on Izuku’s dazed reflection in the fogged glass door. He licked his palm clean, a long, deliberate swipe of his tongue. “Tastes the same,” he said, his voice hoarse. “In your dorm. In my shower. It’s all me.”

He turned Izuku back around, his hands gentle now, cradling his nephew’s flushed face. He kissed him, deep and slow, letting Izuku taste himself on his tongue. “I thought about it too,” he admitted against Izuku’s lips, the confession quiet, almost lost in the water. “Washing you. For years.”

Izuku’s hands, which had been clinging to Katsuki’s shoulders, slid down the hard plane of his chest. His fingers trembled, tracing the water-slicked ridges of his uncle’s abdomen. “My turn,” he whispered, the words almost swallowed by the spray.

Katsuki’s eyes burned into him. “Your turn for what?”

“To…” Izuku’s courage faltered, his gaze dropping to the thick, girthy cock standing heavy and flushed between Katsuki’s thighs. He swallowed. “To take care of you.”

A low noise rumbled in Katsuki’s chest. He didn’t move, just watched as Izuku’s small, freckled hand hovered, then finally closed around his base. The touch was hesitant, almost reverent. Katsuki’s breath hitched, a sharp, audible suck of steam.

“You don’t have to,” Katsuki gritted out, but his hips gave a minute, betraying thrust into the loose circle of Izuku’s fist.

“I want to.” Izuku’s voice grew firmer. He looked up, green eyes wide and earnest in the humid gloom. “Let me, Kacchan. Please.”

He didn’t wait for permission. He sank to his knees on the textured shower floor, the water cascading over his back. From here, Katsuki looked massive, a tower of tense muscle and leaking need. Izuku nuzzled the inside of his uncle’s thigh, inhaling the clean, musky scent of him mixed with sandalwood soap. He pressed a soft, open-mouthed kiss to the jutting hip bone.

“Fuck,” Katsuki breathed, one hand coming to rest on the top of Izuku’s wet curls. Not pushing. Just holding.

Izuku turned his head, licking a slow, flat stripe up the underside of his cock from root to tip. He tasted clean skin and salt and something uniquely, deeply Katsuki. He swirled his tongue around the broad head, coaxing out another bead of pre-cum, lapping it away with a soft hum.

“Look at you,” Katsuki murmured, his thumb stroking Izuku’s temple. “On your knees for me. In my shower.”

Izuku moaned around him, the vibration making Katsuki jerk. He took him deeper, letting his jaw go slack, focusing on the stretch. He couldn’t take all of him—no one could—but he took what he could, hollowing his cheeks, his other hand stroking what his mouth couldn’t reach.

Katsuki’s fingers tightened in his hair. “Slow,” he commanded, his voice strained. “Just like that. No hurry.”

Izuku obeyed, setting a lazy, worshipful rhythm. He licked and sucked, exploring every thick vein, tracing the sensitive ridge beneath the head with the tip of his tongue. He pulled off with a wet pop, panting, and looked up. “Was this part of your fantasy? Me doing this?”

Katsuki’s expression was shattered, raw. “Every part,” he admitted, his chest heaving. “Your mouth. Your eyes looking up at me. All of it.”

Emboldened, Izuku took him deep again, his throat working. He reached between his own thighs with his free hand, finding his clit still swollen and sensitive. He rubbed slow circles as he sucked, the dual sensations making his head spin. The water pounded down on them, a warm, isolating roar.

“Gonna come,” Katsuki warned, his hips beginning to stutter. “Your mouth… shit, Izuku…”

Izuku just hummed again, urging him on, his eyes slipping closed. He wanted it. He wanted the bitter taste, the proof of his uncle’s loss of control because of him.

Katsuki came with a choked-off roar, his release flooding Izuku’s mouth in hot, pulsing streaks. Izuku swallowed, his own body trembling with a secondary, sympathetic thrill. He drank him down until Katsuki was spent, softening in his mouth.

He rested his forehead against Katsuki’s damp thigh, catching his breath. Katsuki’s hand was gentle now, petting his hair. The quiet was different. Softer.

“C’mere,” Katsuki rasped, tugging him up. He pulled Izuku against him, their bodies sliding together. He kissed him, deep and searching, tasting himself on Izuku’s tongue. “You,” he said against his lips, “are a fucking revelation.”

Katsuki’s arms slid down Izuku’s back, guiding him as they sank together to the wet shower floor. Izuku settled into his uncle’s lap, the thick muscle of Katsuki’s thighs a solid bench beneath him. The water rained down on their heads and shoulders, a hot, relentless drumming that enclosed them in a steamy world of their own. Izuku draped his arms over Katsuki’s broad shoulders, their bodies sliding together, and leaned in to kiss him again, slow and deep and tasting of salt and completion.

“We’re gonna prune,” Izuku murmured against his mouth, not moving away.

“Let us,” Katsuki rumbled, his hands smoothing over the swell of Izuku’s ass, holding him close. He kissed the corner of Izuku’s mouth, his jaw, the soft skin beneath his ear. “No one’s banging on the door. Sun’s barely up.”

Izuku relaxed into the hold, letting his forehead rest against Katsuki’s. He traced the shell of his uncle’s ear with his nose. “What do we do now?”

“This.” Katsuki captured his lips again, a lazy, exploring kiss that had no destination. His tongue swept into Izuku’s mouth, and Izuku met it with his own, a soft, wet tangle. “Just this.”

They kissed for long, slow minutes, the only sounds the spray and their shared, humid breaths. Izuku’s fingers carded through the damp spikes of Katsuki’s hair. Katsuki’s palms roamed the freckled map of Izuku’s back, tracing his spine, learning the dip of his waist. It was different. No frantic heat, no driving need. Just presence.

“You’re quiet, nerd.” Katsuki’s voice was a low vibration against Izuku’s chest.

“Thinking.”

“Don’t.” Katsuki nipped his lower lip, not hard. A punctuation. “Just be here.”

Izuku nodded, his eyes closed. He shifted, feeling the soft, spent weight of Katsuki’s cock against his thigh. He felt his own body, loose-limbed and sated, a pleasant ache between his legs. “I am here.”

Katsuki’s hand came up to cradle his face, his thumb stroking over Izuku’s cheekbone. He just looked at him, crimson eyes intense even in the soft, foggy light. The scrutiny made Izuku’s breath catch. It wasn’t hungry. It was… awe. A raw, unguarded thing that was somehow more terrifying.

“Kacchan?”

“Shut up,” Katsuki whispered, and kissed him again, swallowing the question. He kissed him until Izuku melted, until all thought dissolved into the sensation of hot water and hotter skin and a mouth that knew his better than his own.