He honestly doesn’t know when it started.  Maybe as long as he’s been bigger and stronger than everyone else he meets, since he began moving through the world with his low voice and broad shoulders and people took one look at him and decided they knew who he was.

And in fairness, most of the time Geonhak does enjoy being strong.  He likes that he can lift Keonhee like he weighs nothing despite his height, that he can carry Dongju on his back for an hour without getting tired, that he can help staff move heavy equipment after a long day on-site.

He likes the way Hwanwoong’s legs look tiny draped over his own where they sit close together on the couch (even if he knows that Hwanwoong’s leg muscles are probably stronger than steel).

It’s late, maybe midnight, the company building relatively quiet and the practice room door locked.  It’s been a while since they stopped actually rehearsing and just kind of collapsed on the couch, Geonhak engrossed in a mobile game Dongju’d shown him and Hwanwoong seeming to rotate between checking his phone and dozing off every couple of minutes.

“Hey,” Geonhak finally says, nudging Hwanwoong with his knee, “we should head home.”

Hwanwoong groans, tossing his arm over Geonhak’s torso and trapping him further.

“That’s far,” he mutters, pressing his face into Geonhak’s shoulder.  “Let’s stay here, hyung.”

“Woong-ah,” he chides, and knows he’s immediately in trouble when Hwanwoong’s sleepy eyes turn up at him, a little sly and a little knowing.

“Geonhakkie-hyung,” he replies, sickly sweet and pouting, poking Geonhak in the ribs just where he knows he’s sensitive.

An involuntary little noise comes flying out of Geonhak’s mouth, his body trying to twist away from Hwanwoong’s fingers and coming up short due to their tangled legs.

“Hey,” Geonhak says weakly, as much of a warning as he can muster in the face of Hwanwoong’s dangerous little smile.

And it is dangerous, a wire’s edge that he walks, because though he doesn’t know when it started, he does know that some weird, perverse, confused thing deep inside him likes it when someone exploits this weakness of his.  He’s always been crazy ticklish, sensitive all over and unable to hide his reactions, but at some point he found himself dwelling on that desperate feeling of breathlessness, of twisting heat and skin about to burst.  It wasn’t rare that he’d lay awake at night, turning it over in his mind, replaying the last time someone had managed to turn his muscles weak, turn his breath thin and gasping, his mind animal-blank and singularly-focused.

And here, now, wise to absolutely none of it, Hwanwoong digs his tiny fingers into the spaces between Geonhak’s ribs as Geonhak pushes him away in earnest, trying instinctively to get away and losing his breath all the while.

Hwanwoong laughs lightly, a sweet sound likely spurred on by whatever embarrassing face Geonhak's making.  Geonhak manages to detangle their legs and scramble up the couch until his shoulders bump the arm of it, body consumed by the need to escape.  Hwanwoong follows, settling on his thighs to pin him in place, fingers questing.

Normally, Geonhak could easily throw Hwanwoong off, pick him up like he weighed nothing, but like this, with his body in turmoil and brain scrambled and bitten-off laugher tumbling from his lips, he's as weak as a child.  It makes him desperate.  It turns him on, shamefully so.

"Hn, Woong— ah!"  Geonhak’s hands scrabble ineffectually at Hwanwoong’s shoulders, frantic and a little terrified.

Finally, finally, Hwanwoong seems to be satisfied, hands resting on Geonhak's chest, grinning down at him like a cat that's caught a sparrow and is still deciding whether to eat it or keep playing with his food.

And in the span of a breath, a long syrupy moment, he leans forward just enough to feel that Geonhak's gotten hard in his sweatpants.

They've fooled around once or twice before, fumbling in the dark, but this tension feels completely new, even for them.  Hwanwoong's mouth drops into a little pink O, cheeks already flushed from their roughhousing going an even deeper shade.

"Hyung, are you—" he starts, at the same time as Geonhak begins to say,

"I'm so sorry, I didn't mean to—"

Hwanwoong stops him with a hand over his mouth.

"It's… not that weird.  If you like that.  I don't mind."  He tilts his head, blushing even harder as he continues like his embarrassment doesn't exist (a skill Geonhak envies dearly).  "I kinda… it's, uh, kinda fun."

"Oh my god."  Geonhak buries his face in his hands, sure he's red as a tomato at this point.  "Cool.  Okay.  Can we go home now?"

He makes a tiny, mortifying noise when Hwanwoong grabs him by the wrists and pulls his hands away from his face, forcing eye contact that takes all of Geonhak’s limited strength to return.

"Actually, we could, uh… I could keep going? If you wanted."

Geonhak’s sure his eyes are bugging out of his head, tension in every limb even as his dick twitches in traitorous interest.  He’s on a knife’s edge teetering over, every illicit fantasy he’s ever had and repressed flooding back in vibrant detail, brain struggling to come to terms with the fact that someone is here, now, offering to make them real.

“I —” he starts, stops, swallows hard.  “Why?”

Hwanwoong hums, flops down so their faces are much, much closer, perhaps encouraged by the fact that Geonhak hasn’t said “no” yet.

“Because you’re cute,” he says, “and I like messing around with you, and I think it’d be fun.”  His thin lips quirk up at the corners, familiar mischievous confidence returning.  Geonhak wants to kiss him, badly.  Hwanwoong’s gaze traps him, makes him unable to do anything but nod slightly.

Hwanwoong does kiss him, then, playful at first and then quickly filthy.  It takes up every modicum of Geonhak’s focus — the way he sucks on Geonhak’s bottom lip, takes it slowly between his teeth, soothes the hurt with a swipe of his tongue.  They kiss until they’re both out of air, until Geonhak’s hazy enough that he barely pays attention to Hwanwoong’s fingers creeping under his shirt.

He doesn’t notice them until he does, blunt fingernails teasing gently over the sensitive skin of his abs, feather-light.  He gasps loudly into Hwanwoong’s mouth, twisting underneath him as the sensation shoots across his nerve endings.  He can feel Hwanwoong smile into their kiss.  Geonhak’s brain is running a mile a minute, still caught somewhere between shame and arousal and the pure animal response that Hwanwoong’s touch brings out in him.

Hwanwoong pauses for a moment, pulling back to survey Geonhak underneath him.  Geonhak can feel his cheeks burning, sure he looks like a disaster, but Hwanwoong’s gaze is nothing but hungry.

“Good?” he asks, fingers tapping on Geonhak’s hipbones.  Even the threat alone is enough to make Geonhak want to squirm, laughter bubbling up in his throat.

He nods, eyes closed, afraid to open his mouth.

“Just say ‘red’ if you actually need me to stop, okay?”

“W-what?” Geonhak manages, forcing his eyes open.  Hwanwoong flushes.

“I don’t know, I read it somewhere,” he says, looking askance.  “Just… y’know, so you can say stop and I’ll know you don’t really mean it.”

Geonhak presses his lips together and nods again.  Hwanwoong gives him a calculating look, eyes tracing languidly over the flushed skin exposed where his t-shirt’s rucked up around his abdomen.  Slowly, he readjusts so he’s sitting directly on Geonhak’s dick, the layers of fabric doing nothing to dull the sensation that courses through him at the heat and pressure.

“Fuck,” Geonhak curses emphatically, then again, louder, as Hwanwoong shoves his shirt higher and leaves a trail of sucking, lingering kisses up from his hip to the bottom curve of his pec.  Any other context and it might just be arousing, but with his skin oversensitized and muscles ready to jump at the slightest brush, each touch of Hwanwoong’s lips and tongue and teeth send a cascade of anguish across his strung-out nerves.  The laughter in his throat breaks free and echoes into the open air, bouncing off the soundproof walls of the practice room.  After so much teasing it feels like fire, like he can’t get enough air, like he’s out of control and just as desperate for the torment to end as he is for it to keep going.

“I can’t, stop, I can’t —” he gasps out, his voice sounding foreign to his own ears, like someone else is controlling him.  Hwanwoong hums, dragging his tongue slowly, excruciatingly back down the path he’d made before sitting up and surveying Geonhak with lazy cat-eyes, running fingertips up and down the centerline of Geonhak’s abdomen just to keep him shaking and jerking and on-edge.

“Yeah, you can,” he replies, rolling his hips down in a dirty grind that has Geonhak gasping for a completely different reason.  He’s sticky wet in his sweatpants, sure if he looked he’d be swollen red and purple by now, and it’s so goddamn embarrassing that Hwanwoong hasn’t even touched him and he’s already this desperate.

“Please.”  Geonhak doesn’t know what he’s asking for, but maybe that’s okay.  Hwanwoong smiles.

“Lemme get your shirt,” he says, nimble fingers sliding it up Geonhak’s arms until it reaches his wrists.  He makes Geonhak wait, guiding one wrist out of the fabric before twisting it around a few times and then pushing his hand back through the arm-hole.

Geonhak shudders and swallows as he realizes what’s happened.  While his hands aren’t really trapped — he could easily slip out or even rip the shirt if he truly needed — they’re caught enough in the fabric that he can pull and struggle and it still keeps his arms together.

“Okay?”  Hwanwoong asks quietly, ducking down to kiss him again, letting him test the makeshift restraint.  Geonhak can’t speak, can only nod frantically, arousal and fear-pleasure shooting through him like sparks, like flame licking over his skin.

Hwanwoong grins.  “Good.  Wanna make you come from this.”

He guides Geonhak’s bound wrists around his neck — his fingers instinctively clutch at Hwanwoong’s hair, needing something to ground him as he shivers and his hips shift up.

Geonhak honestly had no idea how much being restrained would heighten the sensation, but when Hwanwoong’s fingers trail over the nape of his neck, down his spine to the surprisingly sensitive place at the small of his back, he feels every single muscle in his body lock up like he’s being electrocuted.  He arches so hard he’s afraid his back is going to break, laughter pouring from his mouth despite any effort to control himself.  It has the side effect of grinding his dick against Hwanwoong’s ass, the pleasure hot and acute alongside the searing almost-pain of Hwanwoong’s fingertips dancing along the soft patch of skin at the base of his spine, so sensitive it feels like a lightning strike.  The muscles of his stomach ache already.

“Look at you, hyung,” Hwanwoong breathes, bringing his other hand around to dig into Geonhak’s belly.  Now, with the tickling coming from both sides, Geonhak’s body doesn’t know whether to arch forward or back, caught in the endless, agonizing sensation.

“Stop, stop, please, oh god,” Geonhak gasps, almost hiccuping with his mindlessness.  His muscles feel like jelly, like he couldn’t push Hwanwoong off if he tried.  Completely helpless, all his strength gone.  He might be close to coming — he’s not sure.

“Do you get hot when the others do this to you?” Hwanwoong asks, grinning, a near-manic look in his eyes.  Geonhak can barely think, can barely believe that he could get harder, but a fresh pang of arousal shoots through the haze.

“I — ah, ah, I, yes! Yes,” he manages between paroxysms of laughter.

And it’s true — the other day, Youngjo had hugged him from behind in the dressing room, thoughtlessly playing with the fringe on his shirt, clever hands brushing his waist.  It had been all Geonhak could do to hide his reaction, especially when he’d twisted away and Youngjo had laughed and teased him just a little more for good measure, called him cute in that voice that makes him shiver.

Hwanwoong slows for a moment, withdraws his hand from Geonhak’s back and walks his fingers up and down Geonhak’s ribs one at a time.  The anticipation is intolerable.  Geonhak’s panting.

“Are you gonna come for me, hyung?” Hwanwoong asks, thumb brushing over Geonhak’s nipples, and those have never been ticklish before but Hwanwoong’s got him under some kind of wicked curse because even that touch makes him squirm and whine.  He doesn’t have words anymore, can’t think —

He breaks down in hysterics again as Hwanwoong knuckles into the unbearably sensitive skin under his arms.  His body operates on instinct, attempting to bring his elbows down to protect that vulnerable place but he’s trapped, his wrists strung up around Hwanwoong’s neck and he can’t move, can’t get away, he can’t, he can’t.

“Tell me.”  Hwanwoong’s gaze is too much to bear.  Geonhak wants to hide his face, wants to curl up into a ball so small he disappears, but Hwanwoong’s got him pinned open and exposed and every inch of his skin on fire.  He feels like he’s bursting at the seams, pain and pleasure mingling so completely that he doesn’t know how to tell which is which.

“I’m— I—” he tries, losing his words to hiccupping, sobbing laughter again as Hwanwoong leaves off one of his underarms and drags one set of nails down his ribs, around to that place on his back again, grinding down with his hips, and oh, oh—

He comes with a ragged groan, crushing Hwanwoong to his chest.  It’s so intense that he blacks out for a good half-minute, gasping for air.  Distantly, without really understanding, he can feel Hwanwoong’s fingertips traversing his body, drawing shudders and twitches from him.  He can feel Hwanwoong sliding down a little bit, grinding down on his thigh, frantic and murmuring.  He feels lips on his own.

Reality trickles back slowly.  The first thing he notices is that Hwanwoong’s head is pillowed on his chest.  The second is that his arms are free, and have instinctively wrapped around Hwanwoong.  The third is that he feels like he’s just gone through the absolute hardest workout of his life (and that’s saying something, given the regimen he puts himself through on the regular).

“Ow,” he says, weakly.  Hwanwoong laughs, leaning up to press a kiss to his cheek.

“That bad, huh?” he says, propping himself up on one elbow next to Geonhak as well as he can on the cramped couch.

Geonhak bites his lip, looking askance.  Every worry he’s ever had suddenly comes crashing in, dragging him back down to earth.  Things will be weird now, he thinks, he’s fucked everything up and Hwanwoong was obviously just humoring him and he’ll tell the rest of the group just how much of a freak —

He jerks and gives an honest to god squeak when Hwanwoong wraps his hand around Geonhak’s hip and wiggles his fingers just in the hollow, the skin there still sensitive and tingling.  Hwanwoong giggles in the face of Geonhak’s glare.

“You’re thinking really, really loud, hyung,” he says.  His thin lips quirk into a fond little smile that makes something warm in the pit of Geonhak’s stomach.  “Stop it.  You’re fine.”

Geonhak grumbles, forcing himself to stand up and offering a hand to Hwanwoong.  His legs are still shaky, much to his own embarrassment.  Hwanwoong grins smugly at him as he jumps up, swinging their joined hands between them like a child.

“So,” Hwanwoong says as they gather their stuff from rehearsal, dragging out the word, “if you want to do that again...”

Geonhak freezes in place, staring.  Catching his look, Hwanwoong shrugs.

“What?  Just because it wasn’t my kink before doesn’t mean I didn’t have a good time.”  He leads them out of the studio, flicking the lightswitch behind them.  “And it seems like good stress relief for you, and you’re stressed a lot, hyung.”

Geonhak doesn’t dignify that with a response.

“Besides,” Hwanwoong continues, hushed in case they run into anyone else in the hallway at one in the morning, “next time, I could tie you up for real.”

Geonhak’s head thunks against the cool metal wall of the elevator even as his skin tingles with the thought of a next time.

Hwanwoong, the menace, just laughs.