His cheeks are flushed and his eyes are bright, and he was even willing to let the chief negotiator smear the ceremonial paint on his face. There's an elaborate swirl of blue glittery paint on his cheek, spiralling down his neck, and Spock has to be drugged if he agreed to that, because Kirk doesn't want to think of the alternatives.
The rest are busy drinking the local version of distilled alcohol - Kirk had warned them against anything stronger, as the locals firmly believed in partying down. He hadn't seen so many psychedelics since he was fourteen. He trusts the rest not to do anything too horrifying to his virgin eyes, and anyway it's break night after a whole day of negotiations.
Spock is advancing towards him, measured, flowing movements, like a predator about to pounce. His hips are swaying slightly, emphasising his lithe body.
He pauses two steps in front of Kirk. At this distance, Kirk can't help but notice how dilated Spock's pupils are, and how he's almost shaking with desire. His ears are tipped with silver glitter, and he hopes that Spock did that by himself because he can't stand the thought of someone else seeing Spock so undone, touching his ears, forcing that little purring noise out of him.
"Find somewhere secluded. I have prepared lubricant and other tools. I wish for you to, as you say, 'fuck me into the ground'."
"Forward, aren't you, Spock?"
Kirk touches the line of Spock's jaw, and Spock involuntarily licks his lips.
"I believe you enjoy the company of people who know what they want, Captain."
"Fantastic. This way," and Kirk wonders when Spock got so assertive about this sex thing after their first few times, which mainly consisted of Kirk trying to disprove Spock's assertions that Vulcans did not respond to gentle stimulation.
But no matter.
A secluded tent far away from the celebration, and everyone else preoccupied with watching the locals perform their ritual dances with metal rings and even more glitter. No threats to worry about just then, and naked Spock. Wanting to be fucked.
He was one lucky bastard.
His contemplation of how very lucky he was ceases when Spock arranges what he had prepared on the straw mat, and then begins to remove his clothes.
"Okay, I'm not questioning the lube - nice going there, but...Spock, why do we have a dildo here? And body paint?"
"The chief negotiator had certain ideas about our relationship. She believes that we are a finely matched pair, and thus bestowed their ritual implements upon us to deepen the bond."
"As her ideas about our relationship were mostly true, I did not argue with her. Perhaps we could begin now?"
"...oh god. Yeah. Yeah, okay," and Kirk tries not to think about how he's going to face the chief negotiator the next morning, but instead focuses on Spock's naked body, long-limbed, pale, and his, and tries to think of what he can do with all the things that Spock brought.
He's good at improvising.
He strips, placing his clothes on the mat, then lubes Spock up, stretching him thoroughly, one finger, two fingers, three fingers, as Spock clenches around his fingers and makes a soft noise, desperate to be filled.
Kirk removes his fingers, and before Spock can give him the irritated-cat-noise, he works the dildo in, slowly, inch by inch, until Spock is thrusting back on it, trying to get it deeper, to hit the sweet spot before Kirk stops moving it, and finally it's in. It's wide, but not as wide as Kirk, and it'll do fine to get Spock all hot and bothered, sweaty and needy but unwilling to beg.
He'd love to fuck Spock, but now he wants to take his time.
Kirk dips his forefinger into the glitter paint, then draws a line down Spock's sternum, and Spock twitches upwards, desperate to be touched. The line glimmers on Spock's chest, and Kirk was never an artist but Spock just makes this beautiful. He can't resist adding more to it, delicate silver lines branching out, spiralling over his body, so intricate that they resemble one of the stellar charts that he had once, pinned on his ceiling when he was a cadet, marking the way to places that he could only dream of going.
He shifts Spock and draws sweeping lines down his back, resembling the stylised wings of a bird. He can't resist drawing a vertical line down Spock's spine, terminating at the cleft of his buttocks, which makes Spock push his ass up, mutely trying to get Kirk to touch it. Kirk licks, then bites his buttcheek, and Spock bites his lip in a futile attempt to avoid making noise.
He draws a thin swirl down the back of Spock's hand, terminating at Spock's fingertips, and Spock shivers, clenching around the dildo in his ass, beautiful and naked and helpless.
A diagonal, gently traced up his neck, meeting the spiral swirl on his cheek, and Spock moans softly, his cock getting harder as he attempts to move in order to get some stimulation before Kirk holds him still.
Kirk's fingertip softly traces the contour of Spock's ear, spreading the glitter around it, and the soft pleading noises that Spock makes, combined with the thrusting of his hips, make it impossible for Kirk to wait any longer. Spock's pliant now, and Kirk eases the dildo out.
Spock is blushing green, shimmering with glitter, his pointed ears making him look almost like a fey creature that would disappear in the morning, elaborate whorls and loops and spirals drawn onto him, and in that moment he's the most gorgeous thing Kirk has ever seen.
He's loose and slick, and Kirk enters in one smooth motion as Spock shudders around him. Kirk holds Spock still, leaving shimmering fingerprints on Spock's hips, trying to get the right rhythm and the right angle.
Spock moves with Kirk, pressing back against him in order to get more physical contact, his back radiating heat, smearing the glitter onto Kirk's chest, and finally Kirk hits the right angle, as Spock is moaning helplessly and making noises that in Spock terms mean "yes don't stop please" and humping his hips against the mat, trying to stimulate his penis through frottage. His eyes are wet, and he's in distress.
Kirk grasps Spock's hard cock, just to help him out. That mat can't be very comfortable. Spock almost wails at the stimulation, it's too much, but it's not enough because Kirk isn't moving and there's a cock in his ass but it isn't hitting the spot that he needs it to, and then Kirk starts moving again, with a firm grip on Spock's member, toying with the slit and stroking it.
Spock starts pleading for more. He's not sure what he wants, it's very hard to think because he's so sex-dazed, but he trusts Kirk to know what he needs.
Thankfully, Kirk knows what gets Spock off, because it would be torturous to leave it for longer. Spock is all wet, slick heat around him, and Kirk is so turned on that after three more thrusts, Spock wailing with need all the while, he tugs on Spock's cock firmly, just the way he likes it, and whispers to Spock to come for him as he empties himself into Spock's ass.
Spock moans, and obeys, throwing his head back. The line of his throat shimmers in the fading light, and the whorl of blue glitter that started all of this is almost gone, washed away by Spock's tears of frustration.
Kirk eases out of Spock, and he can tell that Spock feels oddly empty, but now is the time for him to recover.
Glitter is smeared on both of them, and the delicate lines that he's drawn have somehow turned into a depiction of a nebula.
He holds a shivering Spock, who nuzzles against the crook of his neck as he strokes Spock's back, gentling him down.
The sweep of his hand smudges the lines of glitter as he charts his lover's body.