Thought I'd contribute to the K/S cause :D
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It was late into the night, and the the USS Enterprise hummed softly, floating in space. Everyone had retired for the long voyage early next morning, save the 1st Commanding Officer. He was running checks on programs, and doing whatnot. Quietly, the elevator opened and Captain Kirk stepped into the room.
"Spock, I thought I'd find you here." Something in the Captain's voice made the Vulcan look up from his work.
It was desperation, laced with...something else?
Without any warning, Kirk strode across the room to Spock's chair and straddled him.
"What are you-" As Kirk kissed him hard, Spock placed the human emotion he had seen in his lover's eyes - lust. Without breaking the kiss, the vulcan distractedly calculated the last time he had engaged in sexual intercourse with his partner and realized Jim was - what was that word - horny.
"Jim, now is not the time nor place to-" Kirk swore, he could see the faintest tones of pink in Spock's cheeks- "fornicate."
Ignoring the vulcan, Kirk stripped off his shirt and pants. He leaned in close to whisper seductively, "I need to feel the grinding of your dick against mine-" he could feel his partner's nether regions twitch, "-your voice, screaming my name as you release."
Spock always liked it when he talked dirty, and the growing bulge in the vulcan's pants evidenced this. His erection grew more pronounced as the Starfleet uniform was made out of spandex.
Spock could no longer ignore the advances of his lover. He pushed Kirk roughly against the control panels and fucked him hard.
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THE NEXT MORNING
Sulu had a confused look on his face as he and the rest of the crew observed what was left of the control room, just as Kirk and Spock walked in.
"Is there any trouble, boys?"
Puzzled, Sulu replied, "Something- or someone - seems to have wrecked our control paneling last night. It's nothing we can't fix, but the Enterprise won't be going anywhere for a few hours."
Kirk grinned, "That's exactly what I need," and pulled a throughly ravished Spock back out of the room.