Jungkook has never seen the normally composed Dr Kim in such a state before – except maybe earlier when he barged in to interrupt his wardrobe malfunction. Like a scientist observing an experiment, Jungkook takes in every detail of his flustered colleague from the glossy eyes, blushing cheeks, red ears to the increased breath rate, and he wonders what could possibly be causing this strange phenomenon – is Dr Kim perhaps afraid of having his teeth checked? This would certainly explain his on-going passion for their business as well as his objections toward the equipment Jungkook ordered.

He sets the tray of tools onto the small adjustable table alongside the chair and rolls closer on his stool, finding the floor pedals with his foot. He adjusts the lamp and offers Dr Kim the protective eye gear which looks like a futuristic set of sun glasses. The speed at which his colleague grabs the pair makes Jungkook's brow rise again. What is Dr Kim trying to hide so desperately?

"Right then. Are you ready?" he asks and Dr Kim nods, teeth pressing on his full lower lip like he just can't wait. When he squirms on the seat, finally, Jungkook figures it out.

Fear doesn't look like this, there's only one thing that could explain being flustered in such a way, and that's excitement. Taehyung is looking forward to this, he actually really wants this, because it turns him on. Jungkook smiles behind the mask, realising that there is certainly a lot more to Dr Kim than meets the eye.

He adjusts his gloves and immediately at the sight, Taehyung's teeth sink deeper into the rich, pink flesh of his lower lip. A sudden, strange desire to play, to further experiment with the innocent-looking patient at his disposal, tickles at Jungkook, the longer he stares.

How has he never noticed how incredibly lush those lips are, so pink, naturally? The caramel skin has a lighter sheen under the bright light, and with the subtle peach colouring his cheeks, Taehyung looks incredibly... beautiful, the way the rich, dark colour of his hair has a multitude of tones under the spotlight... the way it tumbles down onto the headrest, around his head, so thick and healthy, the soft curl in it practically begging to be touched... pulled, the small voice whispers, tempting and teasing at the back of Jungkook's mind.

He decides to test the waters, temptation he doesn't quite understand brewing somewhere deep inside him. Is Taehyung like this because of what's happening – or because of who is doing it to him? A strange sense of power surges through Jungkook at the possibility that it could even be both.

"Are you scared?" he leans closer to Taehyung, staring at every minute detail in the face like he's trying to catch a thief with a lie.

Taking in the exceptionally smooth contours of the familiar face, it occurs to Jungkook how strange it is that they barely know each other, even after all this time. He doesn't really know what his colleague likes, what he fears and aside from their joint vision of Gentle Dental, he has no idea what Taehyung wants from life. He has never mentioned a partner – the absurdity of that suddenly hits Jungkook like a freight train, heavy and hard. How could anyone so incredibly attractive not have someone?

Jungkook pulls away the dark shades off Taehyung's face, he needs to see the eyes, because the truth of everything, is always in the eyes.

The rich pools of chocolate stare up at him, exceptionally vulnerable, almost pleading. It's not a familiar look on Dr Kim and it does strange things to Jungkook. He can't help but to wonder why he hasn't noticed how much Taehyung has matured, his features aged over the years like fine wine into richness he's rarely, if ever, seen – has he really not noticed, or did he purposefully ignore it all this time... because he liked what he saw, a little too much?

"I'm not sure," Taehyung gulps.

"Well... do you want to try out the equipment?" Jungkook asks softly, voice dropping a notch. Taehyung's pink tongue comes out to lick those luscious lips in a nervous flit and Jungkook is desperately distracted by the sight...

Dr Kim takes a moment to decide, then he nods slowly. There is definitely something different about him, something softer, but Jungkook can't put his finger on it. Whatever it is, he likes it... perhaps a little too much. A feeling tickles in his belly and ideas surge in his mind, without permission.

Jungkook is tempted.

He tears his eyes away with difficulty and picks up one of the straps.

"Which ones?" he follows Taehyung's gaze, it glues to his hand, immediately, with surprising eagerness. Confused by all of the feelings flickering on his partner's face, Jungkook dares it all. "Do you want all of them?"

Taehyung straightens his tie and collar, momentarily appearing more like his usual, confident self and Jungkook can't look away. The way the surprisingly long eyelashes shadow the curve of the peachy cheek, the way the full lips just call to him, made to be kissed. Oh. Something like a memory pushes under his consciousness, fighting to get to the surface, something familiar, from long ago.

"Might as well go with the works, how else will I know how it feels for the patients?" Taehyung says a little loudly, the blush gathering on his cheeks revealing his true feelings when he looks away.

He's lying, Jungkook thinks, increasingly convinced that there is more than he understands to whatever is going on here. Not a moment ago, Taehyung was fighting the straps, now he seems like he's keen to get in them?

"True," Jungkook agrees, just to say something.

He stops his wondering and simply pulls on the straps and buckles them at the centre line of Taehyung's front: over the chest and arms, over the thighs, over the ankles. He tightens them just enough that there is no slack.

"Tighter," Dr Kim gasps suddenly, eyes shining. Jungkook nods, a deep wave of want running along his spine at the change in his patient's breathing at every tightening of strap.

At the final click of a buckle, their eyes meet and it's pure electricity. Jungkook feels it in his skin, along his fingers, how they itch to touch. He realises, or perhaps it's closer to admitting, that it's not a new feeling, it's an old feeling he has buried long ago, and it has just come back to him fully, like a picture perfect memory of a feeling, a gut-wrenching need to have Taehyung begging for him.

The final, absolute confirmation of Taehyung's arousal comes with the obvious bulge and a wet patch over the crotch, in plain sight under the bright light. Jungkook's brain short-circuits for a moment when everything in his mind links up and he understands...

The way Taehyung avoids him but how Jungkook sometimes catches him staring, the way he always seems to avoid being alone with him, at times blushing like some teenager, and what about the way his eyes travelled earlier, all over Jungkook's half-naked body, like he was hungry... Taehyung is weak for him and he wants this – he wants more than just his teeth checked.

Without a word, Jungkook pushes the slender hands into the final cuffs just for the wrists and he tightens the straps. He goes through the other straps, tightening them until Taehyung is completely stuck, like a perfectly wrapped present... Just for Jungkook to do whatever he pleases with.

God. Feeling of utter power surges through Jungkook and it's intoxicating.

Staring down to his helpless patient, Jungkook lowers the back of the seat until Taehyung is facing up, he brings the tools closer and aligns the light to the inviting mouth. He forgets about the sunglasses altogether. He has to see the eyes. Simply has to.

Staring at the pleading pools of desire, Jungkook's cock twitches... the power he holds, the things he could do, right now...

"Open your mouth," he says.