Work Text:
Soo-ho’s obsession has soared to heights he never imagined possible.
A summit so high, it feels like a secret only his heart knows.
Because no matter where he tries to look, his eyes keep drifting back to Si-eun's lips. And what does that always lead to?
Kisses. Endless, soft, desperate kisses.
It’s not Soo-ho's fault. How could it be, when Si-eun's lips are so… impossibly beautiful?
Perfect — pink, plush, the triple P of perfection. And when Si-eun's not smiling, those lips always dip into a pout, soft and irresistible.
Soo-ho's poor heart doesn’t stand a chance. He’s no legendary warrior, just an average delivery boy who somehow landed the hottest, smartest boyfriend imaginable.
He’s convinced he must’ve been a hero in a past life — maybe the one who saved a whole generation from a supervillain.
So every time Si-eun speaks near him, Soo-ho can’t resist. He has to steal a kiss.
He simply can’t help it. Si-eun's lips were made for this — pouty, pretty, silently begging for Soo-ho's.
And Soo-ho'd never say no to his pretty boy.
—
Soo-ho is going to conduct an experiment. A purely theoretical, highly scientific one, of course — for the benefit of society. Nothing else. No ulterior motive. None at all.
He’s going to buy lipstick.
Not for himself — he wouldn’t suit it, and he knows that. But he knows someone who would. Someone who would suit it dangerously well.
The idea first flickered into his mind as he passed a makeup store. He was going to ignore it — what use did he have for makeup? Then he remembered Young-yi's birthday was coming up. A thoughtful gesture. He could pick up some products for her. That was enough of an excuse to walk in.
He hadn’t expected the store to be so… beautiful. Soft lighting, pastel walls, and shelves lined with elegant bottles and boxes. A delicate scent floated in the air — floral, sweet, clean. The place felt like another world, made entirely for softness and shine for women.
Then his eyes landed on the lipstick section.
Rows upon rows of tiny tubes, in every shade imaginable. He wandered over, planning to grab one or two for Young-yi. He was trying to recall what colors she liked — which ones would make her say “You finally got it right” instead of “Wow, punk. Do you even know me?”
But that thought didn’t last long.
Because suddenly, uninvited and unstoppable, another image bloomed in his head.
Yeon Si-eun.
Si-eun, with his perfect lips, already too distracting in their natural state. What would they look like slicked in color? In red? Or something deeper? Something that shimmered just enough to make Soo-ho lose his damn mind?
The thought hit him like a lightning strike. Clear. Hot. Consuming.
And then the intrusive thoughts came, whispering like sin in his ear: Buy it. Buy it. Buy it.
The idea of shopping for Young-yi was long gone. Now it was all about Si-eun. What shade would suit him? What texture? Gloss or matte? Sheer or bold? Would glitter be too much? Was it too obvious to go with red? Or was red just… right?
He stood there, frozen, staring at the display like it held the secrets of the universe. Minutes passed. Maybe hours. He could feel people glancing his way — a guy, standing alone, lost in the lipstick section like he was choosing between life and death.
Eventually, he made a choice.
A reddish lip gloss. Just the right shade — shiny, with a touch of glitter, not too bold, not too plain. It looked like something that would melt beautifully on Si-eun's lips.
And now, Soo-ho couldn’t wait.
—
Standing in front of Si-eun's apartment door, it felt like a million bricks dropped on Soo-ho's head all at once.
When he was in the store, imagining Si-eun wearing lipstick just for him, when he bought it with intent, it hadn’t really occurred to him how exactly he was going to hand it over — or convince Si-eun to actually wear it.
What the hell was he supposed to say?
“Hey, I bought lipstick for you because the idea of your lips dressed in shimmer does very inappropriate things to my brain”?
Yeah. That’d go well.
Fuck.
He raised his hand to press the doorbell, paused, lowered it. Raised it again. Lowered it.
Repeat. Painfully.
Then — “Fuck it,” he muttered under his breath, and jabbed the button.
Ding-dong.
A spike of regret shot through him. Maybe Si-eun wasn’t home. That’d be a blessing, honestly.
But then — footsteps. Slow. Agonizing. Drawing closer from the other side of the door.
Soo-ho immediately panicked. Please let it be Si-eun's dad, he thought wildly.
Pause. Wait. No. That’d be way worse.
A soft voice drifted through the door.
“Who is it…?”
Just like that, Soo-ho's pounding heart slowed, just a bit. That voice always did that to him. Made him feel like the world could end and he’d still be okay if Si-eun was there.
He swallowed. “Your husband,” he croaked out.
A breathy huff came in response. Then — the door creaked open.
And Soo-ho's soul left his body.
Si-eun was standing there in casual clothes, hair a little messy, face bare and soft in the warm light. Unbothered. Unaware. Beautiful.
Soo-ho lost all the air in his lungs. And with it — the last remaining confidence to explain what he’d done.
“What’s that in your hand?”
Shit.
Soo-ho froze. The small bag felt like it gained ten kilograms in his grip.
How the hell was he going to explain that.
He did what he always did when panic rose — smiled. Flashed the charm like a lifeline. Si-eun's eyes sparkled, just a little.
Okay. That’s… something. That’s a good sign. He could work with that.
“Let me in first, huh? It’s hot outside,” he said, already stepping through the doorway like it was his own apartment. Like he belonged there. Si-eun didn’t even blink, just moved aside, letting him in without a word.
Soo-ho made a beeline for the couch and threw himself down dramatically, like he’d just completed a marathon. Like he wasn’t very clearly about to mentally combust.
Si-eun stayed by the door for a second, watching him. Then he stepped in too — quiet and slow. His gaze stayed locked on Soo-ho, like he was dissecting an insect, which was Soo-ho himself.
And the weight of it made Soo-ho's nerves itch.
“So?” Si-eun asked, voice calm. Expectant.
Soo-ho inhaled sharply. Held it. Then let it go in one breath and said,
“…It’s lipstick.”
A beat of silence.
“…What?” Si-eun blinked.
Soo-ho blinked back. “What.”
Like maybe if they both pretended that word didn’t exist, they could undo the moment.
No such luck.
“Why... lipstick?” Si-eun murmured, eyes crinkling just slightly — the tiniest shift, barely there, but Soo-ho knew what it meant.
That was Si-eun's version of a smile.
“For you,” Soo-ho said before he could stop himself.
“…Huh?”
Soo-ho wanted to curl up and die. He didn’t think it would be this awkward. He’d played it out in his head so many times — smooth, cool, flirty. Not… whatever this mess was.
“Look, I only bought it because—because—hell, I don’t even know,” he blurted. “I was just thinking about you. And your lips. Your—your pretty lips. And I thought, 'how would my Si-eunnie's pretty lips look with lipstick on?' And I’m sorry, don’t look at me like—like that, I’m sorry, I’m talking too much, I’ll just go return it—”
“Put it on me then.”
A beat. A silence so sharp, it cut through every word left in Soo-ho's mouth.
Wait.
Did he hear that right?
“…Huh?” he squeaked — voice cracking like glass. The crack alone made him want to hurl himself off Si-eun's balcony.
But Si-eun just stood there, face calm, gaze steady.
“Put it on me,” Si-eun repeated, as if it were the most obvious thing in the world.
Is this punishment for his sins? Was Soo-ho truly that terrible in a past life? Or maybe in the present one.
His palms were sticky. He was sweating. Pathetic. Embarrassing. Get it together, Soo-ho. This wasn’t some unreachable crush from the classroom window — this was Si-eun. His boyfriend.
Still, his nerves didn’t care.
Before he could mentally spiral further, Si-eun sat down beside him — quietly, casually — and scared the soul right out of him.
Without a word, Si-eun reached for the bag and pulled out the cursed little item.
Lip gloss. Reddish. Shimmery. Criminally flirtatious.
Soo-ho couldn’t breathe.
Then — a spark in Si-eun's eyes. That same subtle glimmer he got whenever he was quietly delighted by something.
Wait. Did that mean he… liked it?
Oh.
God.
“It’s pretty…” Si-eun said softly, voice wrapped in amusement, but warm. Real.
Soo-ho winced like he’d been slapped. “You don’t have to lie to me.”
Si-eun turned to look at him, brows drawing slightly together. Confused. Offended. Adorable.
“Soo-ho-yah, I don’t lie. At least not to you.”
Right. Damn. Of course. His honest boy. He loved him.
Soo-ho felt the floor under him tilt just a little. Then — Si-eun smiled.
Fuck. Fuck. Triple fuck.
And then, as if he hadn’t just shattered Soo-ho's heart with that smile, Si-eun tilted his head.
“Well?”
Soo-ho swallowed. “Well…?”
“Put it on.”
Oh. Right.
Fantastic. He was expected to apply lip gloss to his mesmerizing, angel-faced, soft-voiced boyfriend while his hands trembled like he was suffering a full-body spiritual breakdown.
No pressure.
Soo-ho unscrewed the tube with trembling fingers. The gloss caught the light — reddish, glinting, dangerous. He held it like it might explode.
Si-eun leaned in.
Slowly. Silently. Like a dream gliding closer. His gaze was calm, expectant, wide-eyed like he had no idea what he was doing to Soo-ho's internal systems.
He was too close. His skin practically glowed under the soft lighting, and there was a sleepy kind of stillness in his expression — the kind of soft, angelic calm that only made things so much worse.
“I’ve never… I’ve never done stuff like this before,” Soo-ho muttered, half a warning, half a desperate plea for mercy.
Si-eun just blinked at him. “I trust you.”
Soo-ho could feel his heartbeat in his teeth.
He swallowed hard. Lifted the applicator.
“Okay, uh— stay still.”
“I am still.”
“Okay, yeah, well— stay still-er.”
A corner of Si-eun's mouth twitched, amused. But he obeyed. He closed his lips gently, tilting his head just enough to let Soo-ho in.
Soo-ho's hand hovered near Si-eun's mouth. So close. Too close. Shit. Si-eun's breath fanned softly against his wrist, and his lashes fluttered with every blink. He looked like he belonged in a painting — something tender and way too good for this earth.
Soo-ho tried. Really tried. But his hand shook.
“Sorry,” he whispered, laughing under his breath, nervous and weak. “I’m literally shaking like a freak. Sorry—”
“You’re doing fine.”
The words were gentle. Honest. Si-eun, as always grounding him.
Soo-ho exhaled, nodded. Then finally — finally — touched the gloss to Si-eun's bottom lip.
It went on smooth. Shiny. Red, but not too bold. A kiss in color form.
Soo-ho's breath caught in his throat. His entire focus narrowed to this one soft, impossible mouth. He dragged the applicator gently across Si-eun's lower lip, trying not to fall into the curve of it.
Then the top lip.
Si-eun's lips parted just slightly to make it easier.
Soo-ho almost dropped the tube.
“There,” he whispered, voice hoarse. “Done.”
Si-eun blinked. Pressed his lips together instinctively. The gloss shimmered.
Then — he looked at Soo-ho. Really looked. Quiet. Meltingly soft.
“…How do I look?”
Soo-ho didn’t answer.
Couldn’t.
Because Si-eun — sitting there in the soft golden lamplight, gloss catching the glow like dew on cherry petals — looked like he’d fallen straight from heaven and landed square on Soo-ho's chest, crushing every vital organ in the process.
His lips were wet, plush, just tinted enough to draw the eye and then trap it. Like an unspoken dare. His skin looked soft enough to melt on contact. His eyes, half-lidded, dark and calm, held no clue of what he was doing — or maybe they did, and that made it worse.
He looked like a daydream. Like a sin.
Like something Soo-ho wasn’t meant to touch, let alone kiss.
Every part of him was composed and still, legs folded neatly, posture casual, but his lips — Those lips — were dressed to kill. And yet his expression was pure, unbothered, serene.
An angel who had no idea he’d been dipped in temptation.
Soo-ho couldn’t breathe. He wanted to grab him. Worship him. Escape from him. Kiss him until that gloss smeared all over both their mouths and maybe some parts it shouldn’t be.
It was ridiculous.
He was dying.
This wasn’t fair. Si-eun had no right to sit there and look like that. Like all the poetry Soo-ho didn’t know how to write. Like every problem he didn’t know how to solve. All with one look. One goddamn coat of gloss.
It was unholy.
And Soo-ho had never wanted someone so bad in his life.
“Do I look bad?”
Fuck.
No.
Never.
Are you insane? You look like a crime I’m ready to commit without regret.
Soo-ho wanted to scream. Or cry. Or pray. Or do all three at once.
But words failed him.
His throat felt scorched. His heartbeat was a damn riot. The room was spinning. All he managed to croak out was a breathless, flushed —
“Will this answer your question?”
Si-eun blinked — barely — just a flicker of movement.
But before he could part his lips, before that pretty gloss could form another syllable —
Soo-ho pulled him in.
No more thinking. No more trembling hands or godforsaken composure. Just heat, instinct, and that dizzy kind of desperation he’d been holding in since the second Si-eun smiled at him.
Their mouths met with a quiet urgency. The gloss smeared instantly — slippery, sweet, sticky in the best way. Soo-ho could taste it, feel it, lose himself in it. Si-eun's lips were so soft, too soft, and they opened easily under his, kissing him back without a single pause.
Soo-ho felt like he was falling.
Like he’d been falling for ages and finally landed where he was supposed to.
God. If Si-eun was a sin, Soo-ho would gladly burn in the weight of it.
Soo-ho was drowning.
And he never wanted to come back up for air.
Who needed air, when Si-eun's lips tasted like this?
Soft. Sweet. Just the right amount of gloss and warmth and him. His lips fit against Soo-ho's like puzzle pieces, like fate, like some cruel divine joke that Soo-ho didn’t mind being the punchline of.
The kiss actually did feel like a sin, but it tasted like the rightest thing Soo-ho had ever done.
That godforsaken purchase was the best decision of his life. Screw work., screw grades, screw the rest of the world — this was his truth. This was everything.
His thoughts blurred. Spiraled. Crashed.
Si-eun, Si-eun, Si-eun.
He couldn’t think of anything else.
He didn’t even want to.
He kissed harder — lips parting, chasing Si-eun's mouth like it held salvation, as if it was the only thing tethering him to the earth. His hands tightened, greedy, trembling with the weight of how much he wanted.
Wanted Si-eun.
Only Si-eun.
Always Si-eun.
And it earned him something — a sound.
Soft. Whiny. Pretty.
It spilled from Si-eun's throat like an accident, a quiet little gasp wrapped in sugar, Soo-ho broke.
That sound travelled.
Straight to his gut, sparking a heat so sharp it made his breath stutter. Straight to his chest, where his heart clenched, then thundered. And then lower, lower, dragging every scrap of blood in his body with it.
Holy shit.
Si-eun didn’t even know what he was doing, did he?
Didn’t realize how dangerous that sound was?
Soo-ho kissed him like he needed to make him do it again. Like that one soft noise wasn’t enough to live off, and he wanted more, needed more, would burn for more.
Drowning never felt so good.
And he was going under with a smile.
Soo-ho didn’t stop.
He couldn’t.
That soft sound — that whimper — kept echoing in his skull like a fire alarm. Like a siren’s call. Like an addiction kicking in full-force. He needed more.
So he kissed down.
Slanted his mouth away from Si-eun's lips with one last desperate press, and let his lips trail lower — over the corner of Si-eun's mouth, down the curve of his jaw, across that ridiculously smooth neck that smelled faintly like clean laundry and ink and sin.
Si-eun's breath hitched.
Soo-ho's lips moved slower now, but deeper, like he was trying to brand his name onto Si-eun's skin. He kissed down the sharp line of his jaw, then up again, then across to that stupidly delicate spot beneath Si-eun's ear, and—
Another sound.
Fuck.
Involuntary. Like Si-eun didn’t mean to let it out, but couldn’t help it.
Soo-ho lost it.
His hands found Si-eun's hips and pulled him closer, anchoring him, grounding himself, because he had to hold onto something. His mouth moved without rhythm now, just raw, reverent want — lips dragging across soft skin, planting kisses like prayers.
“You’re gonna kill me,” he whispered against Si-eun's jaw, voice cracking, barely audible, wrecked. “You’re gonna fucking kill me.”
He meant it.
Because how could something this soft, this warm, this beautiful, exist — and be his?
Si-eun tilted his head ever so slightly, like he was giving Soo-ho more room. Giving him permission.
Soo-ho kissed him like a man possessed.
Because maybe he was.
Maybe Si-eun had ruined him.
And Soo-ho was helplessly, shamelessly letting him.
Soo-ho was gone.
Utterly and shamelessly, gone.
His lips trailed reverent heat down Si-eun's jaw, his breath uneven, heart thundering. He didn’t even realize he was murmuring Si-eun's name under his breath, as if it was some holy chant, the only word he still remembered.
Until—
Cool fingers curled around his jaw.
Soo-ho froze.
Si-eun pulled him back, gently, but firmly — drawing him away from his neck, away from his skin, until they were face to face again.
Eye to eye.
And oh.
Si-eun looked wrecked.
His lips were swollen, pink and gloss-smeared, eyes hooded and glassy with heat. His breath came out in shallow puffs, chest rising and falling like he was struggling to breathe. His hair was tousled, and his cheeks were flushed a soft, devastating pink.
Beautiful.
Sinful.
Soo-ho smiled — dumb, helpless, ruined by the sight of him. His thumb brushed the edge of Si-eun's lip, sticky with gloss and heat and want.
“You look—”
He didn’t get to finish.
Because Si-eun shoved him.
Not hard — but decisive. Soo-ho hit the couch with a soft thud, breath punched out of him.
And then Si-eun was climbing onto his lap.
Straddling him.
Sitting atop him like he belonged there. Like he’d done it a hundred times before (which he had).
Like Soo-ho was his throne.
Soo-ho kind of forgot how to exist.
His hands found Si-eun's thighs on instinct, holding them like he didn’t trust them to stay — like Si-eun might vanish if he didn’t grip tight enough.
But Si-eun wasn’t going anywhere.
No, he leaned in — slowly, agonizingly — both palms resting on Soo-ho's chest like he was steadying himself.
Their lips were inches apart.
Soo-ho could barely breathe.
And then—
Si-eun kissed him.
Hard.
Unapologetically.
Like he’d been holding back all this time, and had finally snapped. His hands fisted in Soo-ho's shirt, his mouth hot and open and hungry. He kissed with something deeper than desperation — with confidence. With quiet, steady control. Like he was reclaiming something that was already his.
Soo-ho gasped, eyes fluttering shut, head tilting back as he gave in — completely. Utterly.
Si-eun kissed him again.
And again.
And again.
Each one harder, slower, like he was trying to leave his mark, not just on Soo-ho's lips but on every breath, every nerve. His tongue brushed Soo-ho's lip, demanding entrance, and Soo-ho didn’t even think before granting it.
It was dizzying. Consuming. Messy and perfect.
Soo-ho's fingers dug into Si-eun's thighs, gripping hard enough to bruise. He moaned into Si-eun's mouth — couldn’t help it. His whole body burned.
When Si-eun finally pulled back, just barely, a glint sparkled in his eyes — dangerous, amused, and so confident.
Soo-ho stared up at him, chest heaving.
“I thought,” Si-eun said, voice low and wrecked, “this was my lipstick.”
Soo-ho could’ve died happy right then.
Si-eun leaned in again — but not for his lips this time.
His mouth veered slightly to the side, pressing a soft, wet kiss to Soo-ho's cheek. Then another, closer to his jaw. Then one on the edge of his nose, feather-light.
Soo-ho blinked, dazed.
“Wha—”
Another kiss. Right beneath his eye.
Soft. Warm. Glittering faintly with leftover gloss.
Soo-ho stilled.
Then Si-eun kissed the other cheek. Slower. Firmer. Lingering just long enough to leave behind a visible smudge of tinted pink.
Oh.
Soo-ho's breath hitched.
Si-eun didn’t stop.
He kissed the tip of Soo-ho's nose — ridiculously soft. Then the curve of his brow. Then the dip between his eyebrows. His lips moved deliberately, painting Soo-ho with silent affection and a hint of smug possessiveness.
By the time he kissed Soo-ho's temple, Soo-ho was holding his breath, face flushed to his ears.
Then, with a tilt of his head, Si-eun leaned in and bit — lightly — at the corner of Soo-ho's jaw, then soothed it with another kiss.
Soo-ho groaned.
Low and strangled. He was barely holding on.
He could feel it — each kiss left a mark. Not just the lip tint, not just the color, but something deeper. Something that stuck. He could imagine it: his face streaked in faint pink, Si-eun's gloss everywhere, lips and cheeks and skin.
Ruined and claimed.
He didn’t even know what expression he was making anymore, but it made Si-eun laugh — soft and breathy and adorable. He kissed Soo-ho's chin, then leaned back to admire his work.
Soo-ho stared up at him, flushed and stunned.
Si-eun tilted his head.
Satisfied.
It was written in every inch of Si-eun's face.
His eyes — those sharp, unreadable eyes — were now gleaming, relaxed, sparkling, like they’d been lit from the inside out. Mischief danced in them, sure, but there was something else too. Softness. Fulfillment. Warm, open affection that he rarely ever showed, and now it was spilling out all over his expression like he didn’t care who saw.
A brush of red clung to his cheeks, blooming all the way up to the tips of his ears, down the graceful slope of his neck. Like he’d been lit on fire and hadn’t noticed. Or maybe didn’t mind the burn.
And his lips—
They were a mess.
Swollen, kiss-bitten by Soo-ho, stained with that ridiculously pretty shimmer — smeared at the corners, a little gloss catching in the soft dip of his cupid’s bow. Gloss that Soo-ho had put there. Gloss that was now painted all over his face too.
Si-eun looked like a dream. Like desire made flesh.
Soo-ho stared up at him, completely wrecked, chest still rising and falling, brain running on zero thoughts except:
He’s beautiful. He’s mine. I’m so, so fucked. And so, so lucky.
Si-eun tilted his head, mouth twitching like he was holding back another smirk. His voice came soft, easy, smug:
"I'm keeping this."
Ah.
The lipstick.
Soo-ho blinked. Nodded. His throat was dry.
“Yeah,” he rasped, barely functioning. “Of course. It’s yours. Everything— yeah. Yours.”
Si-eun raised an eyebrow, clearly amused.
And then, without warning, he leaned back in — not to kiss this time, but to rest his forehead against Soo-ho's, letting out a quiet sigh.
“I liked it,” he murmured, eyes fluttering shut.
Soo-ho's hands twitched on Si-eun's thighs. He almost choked on his own breath.
“You— you did?”
Si-eun hummed. A quiet sound, honest.
“It felt…” he paused, searching for the word. “Fun.”
Fun.
Soo-ho could’ve laughed. Or cried. Or both.
Because shit, if this was Si-eun having fun, then Soo-ho wanted to spend the rest of his life making him have fun like this.
And if a little lipstick was all it took to see Si-eun look like this — warm, open, glowing in ways Soo-ho had only imagined —
Then he’d buy out the whole damn store tomorrow.