Disclaimer: Sadly, I don't own Criminal Minds or Reid and Morgan. Really, they can keep the rest of the characters, I just want these two. And to rent Garcia every once in a while.

Once

When he had been with women, the idea had been simple: make them come several times before he did. Experience had taught him that he usually only came once.

When he tried to apply this to Spencer, it completely flipped. For one thing, Spencer flipped him on his back and wouldn't let him move, even tied his hands together with a tie. Not that Derek couldn't have freed his hands, but he didn't want to.

He raised his head to watch Spencer, who trailed his hands over every part of Derek's body, finding every sensitive spot, cataloguing every reaction of the dark man. Straddling Derek, every once in a while peering up at him through long lashes… The image alone had Derek hard in seconds.

Spencer's cautious touch around his cock had Derek arching and gasping. The reactions emboldened Spencer, how adjusted his grip and pressure, stroking Derek with one hand while the other played with his balls. Heat built in the pit of Derek's stomach and dropped lower.

He started to tug his hands free to stop the genius. "Spencer… don't… babe…" But Spencer just looked up with those lashes, cutting off Derek's protests. Groaning, Derek tipped his head back as Spencer trailed a single fingernail along his perineum.

"Fuck!"

He was panting from the orgasm as Spencer lazily kissed his way up Derek's body before claiming his mouth. His body was pressed against Derek's, hard cock rubbing against Derek's stomach.

"Spencer… baby… I'm sorry, but-"

Spencer pulled away to see Derek. He smirked. "That was just the beginning."

And for once, it was Derek who came several times. Once from Spencer's hands, once from Spencer's mouth, and once from Spencer riding him.