Archive of Our Own ^beta

Chapter Text

- All image credit belongs to the rightful owner. -

Shin didn’t go to the wedding.

He hadn’t even met her, his dad’s new wife. Just another face trying to fill a space she’d never understand. Shin stayed in his apartment, half-drunk, half-angry, watching the silence rot the clock. It wasn’t until a week later that he got the call.

“They’re moving in. Her kid’s your age. Be nice.”

Her kid.

Shin didn’t care.

Until the front door opened and Saint stepped in.

Saint. 21. Soft-voiced. Polite. Nothing like Shin. He had gentle hands, perfect posture, and that maddening tendency to smile when he was nervous like he didn’t realize how goddamn sweet he looked doing it.

“Hi,” Saint had said, setting his bag down in the hall, looking up at Shin like they were old friends. “So you’re my new brother, huh?”

Shin didn’t answer.

He just stared.

Brown curls, big eyes, buttoned shirt. No piercings, no tattoos, nothing Shin could hate on sight, just clean lines, warm colors, and a voice like melted sugar. The kind of boy you’d trust in a heartbeat. The kind of boy who made people believe in goodness again.

Shin wanted to ruin him on instinct.

~

They weren’t close at first.

Shin stayed in his room. Doors shut. Walls up. But Saint didn’t take the hint, he’d knock gently, peek in, offer food, little attempts at connection that Shin should’ve ignored.

But the first time Saint baked cookies ‘just because’ and Shin took one without thinking, Saint lit up like Christmas and said, “See? I knew you weren’t as scary as you act.”

Shin had to walk away.

Fast.

Because for a split second, he’d imagined dragging that sweet mouth to its knees.

It only got worse from there.

Saint was too nice. Always folding Shin’s laundry without asking. Always giving him the last dumpling. Always offering rides when Shin came home drunk, leaning in with that little worried frown and hands on his arm like he cared.

He never dressed sexy, not on purpose. Just soft hoodies, jeans, sometimes little pajama pants with cartoon bears when he got too comfortable in the house.

But Shin saw the shape of him.

All of him.

And that ass? That tight little curve when he bent over the couch looking for the remote?

That was unholy.

It wasn’t fair.

Saint wasn’t even trying and Shin was losing sleep.

He’d wake up hard, angry, fists clenched in the sheets, the echo of Saint’s laugh in his ears. He started avoiding meals. Showers. Anywhere Saint might be.

Because when Saint leaned in with that sweet, hopeful voice and said “Shin? Are we okay?”

All Shin could think about was bending him over the fucking counter.

And Saint… Saint didn’t notice. Not at first.

But Shin’s body did.

Every time Saint spoke, too close. Every time he crouched to get something from the lower cabinet and that perfect little ass arched up, Shin’s cock twitched. When Saint came home from class in those baggy sweatpants that did nothing to hide the natural bounce in his step… Shin’s mouth went dry.

He started testing him.

It began with the laundry. Saint bent to collect the basket and Shin walked past palm out, sharp slap right to the ass. Just once.

Saint yelped. Turned, wide-eyed. “Did you just?”

“Dirt on your shorts,” Shin lied, not looking back.

Another time in the kitchen, Saint leaned over the counter watching something bake. Shin approached, cool, casual and let his hand graze the round swell of his ass as he passed. Saint stiffened.

“You touched my butt.”

“Did I?” Shin muttered, opening the fridge. “Sorry. Not sorry.”

Saint frowned, cheeks warm. But said nothing.

That made it worse.

~

One night, Shin stood in the hallway, towel slung over his shoulder, bare chest damp with post-workout sweat.

“Shower’s open,” he said, glancing over.

Saint looked up from the couch. “You can go first.”

“I meant… wanna just take it together?”

Saint blinked. “Together?”

“Yeah,” Shin shrugged. “Time saver.”

A pause. Saint tilted his head, like it hadn’t even occurred to him this was weird.

Then “Okay, sure brother.”

Shin’s stomach twisted.

The steam filled the shower fast.

Saint stepped in behind him, shyly. His body pale, delicate, pink in the heat, water dripping from his curls. Shin’s gaze dropped once, just once and it hit him like a punch to the gut.

Saint was gorgeous.

Soft chest, slim waist… and that fucking ass. Plush, tight, swaying slightly as he reached for the soap. Shin turned fast, biting his cheek to hold back a groan.

He tried to calm himself. He really did.

But the second that bar of soap slipped from Saint’s hand and clattered to the floor-

“Oh,” Saint murmured. “Oops.”

He bent to pick it up.

Shin’s cock throbbed. Fully hard now, twitching in open air. His breath went shallow, eyes locked on the slick curve of Saint’s back, the way the water streamed between those cheeks like temptation made wet.

Saint stood and turned, blinking. “You okay?”

Shin jerked away, mumbling something. But that image burned itself into his skull.

He jerked off three times that night. None of it helped.

~

A week later, Saint knocked on Shin’s bedroom door.

“Can I sleep here?” he whispered, hoodie swallowing his frame. “Bad dream.”

Shin stared.

Saint crawled into bed without hesitation, laying close. He even grabbed Shin’s hands and wrapped them around his own waist. “There,” he whispered sleepily. “Hug me.”

Shin held his breath.

He was hard instantly. Pressed up against Saint’s ass, chest tight, breath shaking.

Saint snuggled deeper. “You’re warm.”

Shin’s hips moved.

Just once.

Saint gasped. “Shin.. Do it again.”

Shin did.

Saint whimpered. “Feels nice…”

And Shin couldn’t stop. Humping slow, grinding his cock into the curve of Saint’s ass through their boxers, breathing ragged while Saint moaned softly under the covers, holding Shin’s hand like nothing was wrong.

That became their new routine.

Night after night. Touching. Rubbing. Saint would even press his ass back when Shin moved too slow. Once, he even whispered, “Faster… I like when you’re rough…”

They never talked about it.

They just did it.

And Shin? He was losing his mind.

Because Saint wasn’t just the prettiest thing he’d ever seen.

He was his stepbrother.

And one night, Shin was going to fuck him.

And neither of them would pretend it was brotherly again.

It started with the grind, every night under the covers, cock to ass, Shin’s breath heavy behind Saint’s neck as he rutted through boxers, releasing against those pillowy cheeks, Saint whispering “Mmm, again tomorrow?” like he didn’t know what he was doing.

But it didn’t stop there.

Because one night, Shin came in hard, already half-hard from just the sound of Saint brushing his teeth and when he slid into bed and Saint scooted his ass back like always, sleepy and smiling, Shin didn’t bother with subtlety.

He reached down.

Hooked two fingers into Saint’s waistband.

And pulled.

Boxers and pajama shorts slid down those soft thighs in one long, smooth motion.

“Shin?” Saint mumbled, turning his head, confused.

Shin didn’t speak. Just let his cock spring free and dragged himself right into the space between Saint’s bare cheeks, thick head pressed between them, riding that valley slow, hot, heavy.

Saint gasped.

“Wha… you’re touching it,” he whispered, voice small.

“You’re warm,” Shin muttered, voice rough against his ear. “I needed to feel you.”

Saint’s body tensed, then softened. He wiggled back just a little, and his cheeks swallowed Shin’s shaft like it belonged there.

“Oh…”

They didn’t move for a moment.

Just Shin’s cock, nestled tight between Saint’s bare ass, skin to skin, pulsing hot. Shin rolled his hips once, slow, gliding along that perfect, slick groove.

Saint whimpered. “That feels…”

Shin kissed the back of his neck. “You like it?”

Saint nodded. “It’s very warm…”

He pulled Shin’s arms around his waist again. Made him hold tighter. Like he didn’t realize how close Shin’s cock was to breaching that last wall. Like he didn’t care.

“Keep it there,” Saint whispered sleepily. “It helps me sleep…”

Shin groaned quietly. Ground himself deeper between those cheeks and didn’t pull back. Let the tip throb right at that untouched entrance.

It was just a matter of time now.

One night, Saint would moan. Shift. Ask him to go further.

And when he did?

Shin wouldn’t stop.

- To be Continued -

Chapter Text

- All image credit belongs to the rightful owner. -

Saint didn’t even hesitate anymore.

He came into Shin’s room like he belonged there, hoodie slipping off one pale shoulder, curls damp from his shower, pajama shorts already riding low like he wanted Shin to see how easy he was to touch.

He padded barefoot across the room, soft and unguarded, and climbed straight onto Shin’s bed, curling into his lap like his body knew exactly where to go.

“Hold me,” he whispered, the same words every night.

Shin’s arms wrapped around him before he could stop himself. His cock was already stirring under Saint’s weight, fat and aching, pressing hot against the curve of his ass through thin layers of cotton. His jaw locked, teeth grinding.

“You really can’t sleep without me now, huh?” Shin muttered.

Saint blinked up, doe-eyed, baby-powder sweet.

“Not unless you’re here.”

That was all it took. Shin’s restraint snapped.

He gripped Saint’s hips and ground up, cockhead dragging sticky against the back of his shorts. Precum soaked into the fabric instantly, leaving a wet, hot patch that made Saint gasp.

“Shin- wha- oh! You’re- leaking again…”

“Yeah,” Shin growled, rutting harder, smearing himself across that soft cleft. “That’s all for you Saint.”

Saint’s cheeks flushed pink, lips parting in shock. “But… I didn’t do anything…”

“You don’t have to.”

Shin bit down on his jaw, mean but tender, cock throbbing against him. “Existing is  enough. You make me this hard just by breathing near me.”

Saint whimpered, thighs squeezing tighter around Shin’s lap, hole twitching under the pressure.

“…It feels like you’re trying to go inside…”

“I am.” Shin’s voice cracked low, his cock pressing harder at the rim through the damp shorts. “And tonight, I’m not stopping.”

Saint froze, eyes wide, clutching Shin’s shoulders like a lifeline. “But I’ve never done—”

“I know,” Shin cut him off, pulling his shorts down in one rough motion, baring soft thighs, pale ass, pink hole trembling. “You’re a virgin, so am I. That’s why this is happening.”

~

Shin lined up, cock swollen and dripping, head pressing hot and sticky against Saint’s untouched rim.

Saint’s whole body shook, his voice small, terrified, sweet. “It’s too big- it won’t fit…”

Shin kissed his damp curls, mean words wrapped in comfort. “It’ll fit. You’ll take me. You were made for my cock.”

He shoved slowly.

The blunt head forced past resistance, stretching Saint wide with a wet, obscene sound. Saint cried out instantly, tears welling, hole spasming around the intrusion.

“Ahh~ Shin! It hurts— it burns-”

“Shh.” Shin kissed his temple, groaning as his cock sank deeper inch by inch. “Take it, yeah? Take me like a good boy. You’re mine now.”

Saint sobbed, face pressed into Shin’s neck, clinging tighter, body trembling. His hole choked Shin’s cock, squeezing like it was trying to push him out and suck him in at the same time.

“Fuck~ ngh-” Shin hissed, vision going white. “So tight. You’re splitting on me. Lord, you’re perfect.”

Finally, he bottomed out, balls pressing flush against Saint’s ass, cock buried to the hilt. He trembled, forehead against Saint’s curls, chest heaving.

“Saint,” Shin groaned, kissing his damp cheek. “I’m inside. All the way.”

Saint whimpered, tears streaking down his flushed face. “So full— I can’t- oh god, Shin- I feel like I’ll break—”

“You won’t,” Shin whispered, rocking shallow, wet noises obscene in the dark. 

The first thrust made Saint scream.

Shin pulled out halfway, then slammed back in wet and brutal, their bodies smacking hard.

Saint’s hole stretched around him, clenching helplessly. His nails dug into Shin’s shoulders, tears spilling as he sobbed.

“Too big—it’s too much—”

“It’s okay baby,” Shin growled, kissing him rough to swallow the cries. “You’re taking my cock so well”

Saint moaned against his lips, broken, trembling. “…It- it feels good…”

“That’s my baby,” Shin muttered, pounding harder, dick hitting deep. “Good boy. Taking me like you were made for this.”

Saint whimpered with every thrust, hole slick now, wet from Shin’s pre and his own body’s surrender.

The burn blurred into something else, sharper, hotter. His voice cracked high.

“Shin it’s rubbing something— ahh~ it feels so weird—”

“That’s your spot,” Shin snarled, hips snapping rougher. “And I’m gonna fuck it until you’re cock-drunk.”

Saint screamed into his shoulder, body jerking, ass pushing back without thought.

Minutes bled together in slick, messy rhythm. Shin fucked him hard, bouncing him in his lap, every thrust wet and obscene. Saint cried and moaned, hole fluttering around the cock battering him open.

“Listen to you,” Shin rasped, biting his neck. “Crying like a brat, clinging like you’ll die without me. Say it… say you’re mine.”

Saint sobbed, voice breaking. “I’m yours—Shin- I’m yours— always-”

Shin’s cock pulsed deep, balls slapping wet against him. He kissed the tears from his face, mean and soft at once. “That’s my angel. My pretty bun. No one else gets to touch you. Just me your brother yeah? ”

Saint’s body trembled, his untouched cock leaking untouched between them. “I— ngh~ ah~ I feel funny- Shin I think- I think I’m gonna—”

“Cum,” Shin ordered, fucking harder, faster and brutally like a madman.

Saint screamed, body seizing, spilling untouched all over his stomach, thick ropes painting both their skin. His hole clenched down violently around Shin’s large cock, milking it.

“Fuck—” Shin snarled, thrusting through it, cock pulsing. “Take it, bun. Take my cum.”

He spilled inside him, hot and heavy, filling that virgin hole until it overflowed, dripping down Shin’s thighs.

Saint collapsed forward, face against Shin’s chest, trembling and sobbing softly. “It’s leaking—Shin it’s dripping out..”

“As it should.” Shin kissed his curls, holding him tighter, cock still buried deep. “You’ll leak for me every night.”

Saint whimpered, clinging tighter. “Don’t let go…”

“Never,” Shin whispered, rocking his hips again, shaft hardening inside the ruined heat.

Saint gasped, wide-eyed. “Y-you’re still… hard?”

“Yeah.” Shin smirked, grinding deeper, cum squelching between them. “Round two, baby. I’m not done with you.”

~

The second round was worse. Better. Shin flipped Saint over on his stomach, pressing his face into the pillow, ass up, cock already sliding back in with a wet, messy squelch.

Saint moaned high, broken. “It’s still inside me- so big—I can’t!”

“You can.” Shin slammed in deep, fucking harder than before. “This hole belongs to me now.”

Saint clung to the sheets, sobbing, every thrust shaking the bed. “Shin—oh god—ahhh! it’s too much”

“Say you love it,” Shin snarled, spanking his ass hard leaving his red handprints on them.

Saint cried out, body arching. “…I l-love it- love your cock so m-much”

“That’s right.” Shin kissed his spine, pounding harder. “Say you’ll never let me go.”

“Never. never- always yours.”

“Such a good little one,” Shin groaned, spilling inside him again, messy, filling him twice over.

~

By the third round, Saint was cock-drunk.

He lay on his back, legs hooked over Shin’s shoulders, hole gaping wet, dripping cum. His face was flushed, curls plastered with sweat, tears drying on his cheeks.

Shin held his thighs wide and fucked down into him, mean and relentless, filling him again and again while Saint babbled nonsense.

“Feels good- so good- Shin—I can’t stop—I don’t wanna stop—”

“You won’t,” Shin growled, slamming in deep, cock hitting his spot again and again. “You’ll take this cock until you can’t think straight. You’re mine brother. Always mine.”

Saint sobbed, clinging to his wrists. “…Always… yours…”

- The End -