The greenhouse door clicked shut behind them, sealing them in the warm, damp dark.
For a second, they just stood there, breathing. The air was thick with the scent of soil and blooming night-blooming jasmine. Moonlight poured through the glass roof, painting Katsuki’s sharp features in silver and shadow.
Izuku’s heart hammered against his ribs. “Kacchan.”
“Don’t,” Katsuki growled, but he was already moving, closing the distance. His hands came up, rough palms framing Izuku’s face. “Don’t fucking talk.”
He kissed him. It wasn’t gentle. It was a claiming—a hard, desperate press of lips that tasted like coffee and guilt. Izuku gasped into it, his own hands flying up to clutch at Katsuki’s shirt, fingers digging into the hard muscle of his back.
They broke apart, panting.
“This is so sick,” Izuku whispered, even as he leaned back in, chasing Katsuki’s mouth.
“I know.” Katsuki caught him, biting at his lower lip. His hands dropped, fumbling with the hem of Izuku’s sweater. “Off. Get this off.”
Izuku yanked the sweater over his head, his curly green hair a wild mess. The cool air hit his skin, raising goosebumps over his freckled chest. Katsuki’s gaze dropped, hot and heavy, to the small, soft curves of his chest, to the large, puffy nipples already pebbled tight.
“Look at you,” Katsuki breathed, the words ragged. He palmed one, his calloused thumb rubbing roughly over the nipple. Izuku cried out, back arching.
“Your turn,” Izuku demanded, his own hands pulling at Katsuki’s shirt. “I want to feel you.”
Katsuki tore the shirt off himself, the fabric ripping at the seam. The moonlight caught the defined planes of his chest, the powerful arms. Izuku’s mouth watered. He leaned forward, pressing an open-mouthed kiss to Katsuki’s sternum, tasting salt and heat.
“Pants,” Katsuki ordered, his voice a low rumble. His fingers made quick work of Izuku’s fly, pushing the fabric down over thick thighs. Izuku kicked them away, standing naked and shivering in the humid air.
Katsuki’s eyes drank him in. “Fuck. Always so fucking ready for me.”
His own jeans were next, shoved down just enough to free his cock. It sprang out, thick and heavy, the foreskin already drawn back from the flushed, leaking head. Ten inches of desperate need.
Izuku reached for it. His hand, smaller and paler, wrapped around the base. He couldn’t close his fingers all the way. He stroked, once, a slow glide that made Katsuki hiss and buck into his grip.
“Not like that,” Katsuki snarled, grabbing Izuku’s wrist and pulling his hand away. “I don’t need a handjob.”
“I want to feel your mouth,” Katsuki said, his voice gravel. He took a step back and sat heavily on the wide, cushioned bench nestled among the ferns, his thick cock standing straight up from his open jeans. The moonlight caught the slick bead of precum at the tip. “Get over here.”
Izuku’s breath hitched. He was still naked, shivering. He took a step, then another, the warm, damp soil of the path cool under his bare feet. He stopped just in front of Katsuki’s knees.
“You look fucking terrified,” Katsuki observed, his red eyes gleaming. His hand came up, not to guide, but to fist in Izuku’s green curls. He didn’t pull yet. Just held. “You don’t have to.”
“I want to,” Izuku whispered, the lie and the truth all in one. He sank to his knees on the soft moss between Katsuki’s feet. The scent of him here was overwhelming: clean sweat, musk, the sharp, dark smell of his arousal. Izuku’s own pussy clenched, empty and aching.
Katsuki’s grip tightened. “Then do it.”
Izuku leaned forward. He nosed along the hot, heavy length, breathing him in. He pressed an open-mouthed kiss to the throbbing vein on the underside. Katsuki jerked, a ragged curse slipping out.
“Stop teasing, nerd.”
Izuku looked up at him, the moonlight making his green eyes look huge. Then he opened his mouth and took the head inside.
Heat. Salt. The specific, bitter taste of him. Izuku’s eyes watered as he relaxed his jaw, taking more, the thick girth stretching his lips. He couldn’t take it all—he knew he couldn’t—but he tried, sinking down until his nose pressed into coarse blond hair, his throat convulsing.
Katsuki groaned, a deep, shattered sound. His hips twitched upward, forcing another inch. “Fuck. Just like that.”
Izuku pulled back, gasping, a string of saliva connecting his lips to the slick crown. He lapped at the slit, drinking the precum that welled up. His own hands were trembling where they rested on Katsuki’s thick thighs.
“Use your hands, too,” Katsuki ordered, his voice strained. “Work the base. Don’t just suck the tip.”
Izuku obeyed, one small hand wrapping around what his mouth couldn’t contain. He began to move, a messy, wet rhythm of mouth and fist. The sounds were obscene: slick pumps, choked gags, Katsuki’s harsh breathing.
“Look at me,” Katsuki gritted out.
Izuku dragged his gaze up. Tears tracked through the freckles on his cheeks. Katsuki watched him, his expression savage, his own face flushed with a mix of fury and pleasure.
“You’re good at this,” Katsuki said, the words a low rasp. “Think about this when you’re with your perfect boyfriend? On your knees for me?”
Izuku whined around his mouthful, the vibration making Katsuki curse again. His hips began to piston upward, gentle at first, then harder, setting a brutal pace. Izuku took it, his throat working, tears flowing freely now.
Katsuki’s free hand came down to cradle his jaw, thumb stroking the stretched skin. “Gonna cum in your mouth. You’re gonna swallow it. Every drop.”
Izuku’s whole body shuddered. Between his own legs, he was dripping, a hot pulse of need with nowhere to go. He redoubled his efforts, hollowing his cheeks, sucking hard.
Katsuki’s control snapped. “Izuku—” His back arched off the bench, his grip becoming painful in Izuku’s hair. He thrust deep, once, twice, and held. Heat flooded Izuku’s mouth, bitter and thick and endless.
Izuku swallowed, convulsing, again and again, until Katsuki went still, spent. He softened slowly in the wet heat of Izuku’s mouth.
For a long moment, the only sounds were their ragged breaths and the distant hum of the greenhouse heater. Katsuki’s hand loosened in Izuku’s hair, becoming almost a caress.
Izuku pulled off, wiping his mouth with the back of his hand. He stayed on his knees, looking up, waiting.
Katsuki looked down at him, his expression unreadable. “Get up,” he said, his voice quiet now. “Your turn.”
Katsuki stood, his movements deliberate, and pulled Izuku up by the arm. He didn't speak. He kissed him, messy and raw, his tongue claiming the taste of himself still in Izuku's mouth. He walked Izuku backward until the back of his knees hit the bench.
"Down," Katsuki growled against his lips, and Izuku sank onto the cushioned seat, his bare back pressing into the cool, soft cushion.
Katsuki followed him down, covering him, his weight a familiar, devastating anchor. He kissed a trail from Izuku's swollen lips, down his jaw, over the frantic pulse in his throat.
"So fucking soft," Katsuki muttered, his mouth moving lower, over the small, budding swell of Izuku's chest. He took a puffy nipple into his mouth, sucking gently, then worrying it with his teeth until Izuku arched with a sharp cry.
"Kacchan—"
"Quiet." The command was rough, but his hands were steady as they smoothed down Izuku's trembling sides, over the curve of his hips. He kissed lower, across the constellation of freckles on Izuku's stomach, his breath hot on the sensitive skin.
Izuku’s hands fisted in his own hair. "Please."
"Please what?" Katsuki didn't look up. His thumbs hooked into the crease of Izuku's thighs, spreading him open on the bench. The humid air kissed his exposed, shaved skin.
“Where do you want my mouth, huh nerd?” Katsuki’s voice was a low rumble against his skin. He didn’t wait for an answer. He just bent his head and licked a slow, flat stripe up the length of Izuku’s pussy.
Izuku’s back bowed off the bench, a broken sound tearing from his throat. “Oh god—”
“Tastes like you’ve been thinking about this all day,” Katsuki muttered, his breath hot against his soaked skin. He didn’t tease. He ate.
His mouth was skilled, relentless. He used the broad of his tongue, then the pointed tip, circling his clit before sucking it gently between his lips. Izuku’s hands flew from his own hair to tangle in Katsuki’s spiky blond strands, not to push, but to hold on.
“Kacchan, that’s— right there—”
“I know where it is,” Katsuki grunted, the vibrations making Izuku sob. He slid two thick fingers inside him without preamble, crooking them up. Izuku clenched around them instantly, dripping.
“You’re so fucking wet for me. Always are.” He fucked him with his fingers in a steady, deep rhythm, his mouth never leaving him, drinking him down. The sounds were obscenely wet, open-mouthed and hungry.
Izuku’s thighs trembled, trying to close, but Katsuki’s shoulders held them wide. “I can’t— it’s too much—”
Katsuki pulled off just enough to speak, his lips glistening. “You can. You’re gonna cum on my tongue.” He plunged his fingers deeper, twisted them, and went back down.
The orgasm built like a fault line shifting, deep and inevitable. Izuku’s cries grew higher, fractured. His hips stuttered against Katsuki’s mouth, seeking more, seeking everything. “I’m— Kacchan, I’m gonna—”
Katsuki hummed against him, a final, devastating permission. The world went white and silent behind Izuku’s eyelids. He came with a choked scream, his body seizing, a hot gush of release flooding Katsuki’s mouth and chin.
Katsuki worked him through it, gentling his tongue, swallowing every pulse until Izuku collapsed back onto the bench, boneless and shuddering. Only then did he lift his head, wiping his mouth with the back of his hand. He looked down at Izuku, sprawled and ruined in the moonlight, his own expression stark. “See? Didn’t have to beg.”
Katsuki stood, kicking his jeans the rest of the way off. He loomed over Izuku, his thick cock flushed and heavy against his thigh. He nudged Izuku’s trembling legs wider and settled between them, the head of his cock notching against slick, swollen heat.
“Look at this,” Katsuki breathed, his voice gravel. He rocked his hips, a shallow, teasing push that made Izuku gasp. “Soaked. You’re fucking dripping for me.”
Izuku’s hands scrabbled at the bench cushion. “It’s— it’s because of you.”
“Damn right it is.” Katsuki dragged the broad head through his folds, coating himself, a slow, deliberate glide that had Izuku’s back arching. “You hear how wet you are? That slick little sound?”
“Kacchan, please.”
“Please what, nerd? Use your words.” He pressed in, just the tip, a stretch that burned so good Izuku saw stars. He stopped.
Izuku whined, his hips trying to chase it. “Fuck me. Please, just fuck me.”
Katsuki’s eyes were black in the moonlight. “Since you asked so nice.” He pushed forward, a slow, relentless invasion that stole the air from Izuku’s lungs. He was so big, so thick, the stretch a perfect, consuming ache. Katsuki groaned, a deep, shattered sound. “Christ. You take me so good. Like you were made for it.”
He pulled out almost all the way, then slammed back in, setting a deep, punishing rhythm from the start. The bench creaked. Izuku cried out, his nails digging into Katsuki’s forearms.
“Look at you,” Katsuki grunted, his thrusts never faltering. “My perfect nephew. My good boy. Ruined for anyone else.”
“Only you,” Izuku sobbed, the words torn from him. “It’s only ever you.”
Katsuki’s pace faltered for a second, his expression tightening. Then he drove in harder, faster, bending to crush his mouth to Izuku’s. The kiss was all teeth and shared breath. “Gonna fill you up,” he growled against his lips. “Gonna make sure you feel me for days. When your pretty boyfriend touches you, you’ll remember who you really belong to.”
“I know,” Izuku gasped, his legs locking around Katsuki’s waist. “I know, I know—”
Katsuki’s hand slid between them, his thumb finding Izuku’s clit, rough and perfect. “Cum for me again. Do it. Squirt all over my cock.”
The command, the friction, the fullness—it was too much. Izuku shattered, a raw scream echoing under the glass roof as his body convulsed, a hot gush of release flooding between them. Katsuki fucked him through it, his rhythm turning brutal, chasing his own end.
“That’s it,” he snarled, his thrusts turning erratic. “Take it. Take all of it.” He buried himself to the hilt and went rigid, a broken shout muffled in Izuku’s shoulder as he pulsed deep inside, heat spreading, claiming.
They collapsed together into the damp, tangled cushion, spent and breathing raggedly. The humid air carried the scent of sex and wet earth. Katsuki’s weight was crushing, real. He didn’t pull out.
After a long minute, Izuku whispered into the silence. “We’re sick.”
Katsuki’s breath hitched. He turned his head, his lips brushing Izuku’s ear. “Yeah.”
Izuku’s hand found Katsuki’s jaw in the dark, turning his face. “I don’t want to stop.”
Katsuki’s eyes were closed. He let out a slow breath. “I know.”
“Do you?” Izuku’s voice was raw. “Do you want to?”
Katsuki’s eyes opened, crimson and exhausted. “No.” The word was a graveled surrender. “Fuck no, I don’t.”
“Then we don’t.” Izuku’s thumb stroked the stubble on Katsuki’s cheek. “One more week and four days. Until Christmas. Any chance we get.”
A bitter, hollow laugh escaped Katsuki. “You’re signing a death warrant, nerd. For both of us.”
“I know that, too.” Izuku leaned up, his lips a breath from Katsuki’s. “Promise me.”
Katsuki stared at him, his gaze tracing every freckle the moonlight could find. He saw the ruin he’d made, the ruin he craved. He nodded, once. “Any chance.”
Izuku kissed him then, a seal on the pact. It wasn’t hungry or desperate like before. It was slow, deep, and terrifyingly final. Katsuki kissed him back, his hand tangling in green curls, holding him there as if he could stop the dawn.