Disclaimer: I own nothing Criminal Minds related.

Title: Just This Once

Rating: R

Warnings: Slash, sex, lacking of fluff

Prompt: For Criminal Minds Kink Meme IV on LJ:

Morgan/Reid- Angst. First and only time. Unrequited love.

Morgan says this would be a one-time thing...so Reid promises himself he will make the most of this gift. He maps out his body, to memory, and vows never to forget the sounds the older man makes, when his fingers dance across his skin.

Thank you to everyone who reviewed the last chapter and I'm terribly sorry that I wasn't able to respond to any of them. Unfortunately I never seem to have as much time as I would like. But I promise that I read everything and each and every comment means the world to me. Thank you so much.

"Just this once, Pretty Boy, just this once," Morgan whispered for the third time that evening, his thick fingers entangled within Spencer's brown locks. The darker male hissed in pleasure, pulling the younger male closer as his hips bucked, murmurs of, "God yes," following suit; "that's it... god, so good. Come on Pretty Boy, just a little bit more—"

And for the third time that evening, Spencer said nothing. How could he?

He didn't want to remember that this wasn't for forever. He wanted to pretend that Morgan was his.

So he didn't protest as Morgan guided his mouth further down on his length, enjoying the moans of delight that escaped the older male, the incoherent coos of encouragement. Pleas for more, groans that he was close, so very close.

Spencer closed his eyes, savoring Morgan's rich voice that changed octaves as he continued to suck and lap, as he flicked his tongue across the oh-so-sensitive spots he was learning all about. He allowed the words to float across his mind, repeating and overlapping one and another again and again, past mixing together with present, to be imprinted in his mind, knowing that this would never again happen so these words would have to last him for forever.

His fingers roamed across the expanse of the older male's skin, dancing in a rhythm that only made sense to Spencer. He mapped the flesh, he plotted the points that made Morgan moan and the nerves that made Morgan buck, the sensitive areas that made Morgan hiss and grip his hair all the more tightly, the encouraging strokes that made Morgan swear and slur together sentences containing lewd promises.

Morgan was beautiful.

His smell, his flesh, everything.

And Spencer swore to himself that he would never forget any part of it as Morgan once again murmured, "Just this once," as if he felt the need to remind Spencer again and again. As if Spencer hadn't heard him before. As if Spencer would forget.

But Spencer could feel Morgan's balls tighten ever so slightly, the other's form trembling beneath his touch. Morgan was close, so close, but Spencer couldn't let the other cum, couldn't let this be over so quickly.

When he pulled off of Morgan's length, the older profiler let out a hiss of displeasure mixed with annoyance. Dark eyes snapped open to stare at the genius, Morgan growling a warning, "Pretty Boy."

Spencer merely smirked because he knew that the second he showed Morgan his true longing, that he didn't want this to just be a one time sexual encounter, Morgan would leave. Morgan would call it off because Morgan couldn't handle something like that. So Spencer had to pretend that he was alright with the premise that this would never happen again because he was being given a gift and he intended to savor every last moment of it.

So he smirked, eyes sliding into a half lidded state as he slowly crawled up, placing slow, deliberate licks and nips to the expanse of Morgan's beautiful flesh, to the spots he had already become so familiar with, to the well developed muscles that made Spencer's mouth water. He wanted to kiss the flesh, but kissing was too personal, too intimate for just once.

"We're just getting started Morgan," he practically purred, pulling away least he give into his desire to find out what it was like to kiss Derek Morgan, to kiss any part of Derek Morgan. "There is so much more I plan to do to you. Don't leave me disappointed."

And his taunts received a moan and a challenging growl all mixed together. Chills rolled down Spencer's spine as Morgan suddenly grabbed him by the hips and forced him back against the bed, the darker male straddling with Spencer with a smirk of his own. "Disappointed, huh?" he asked in a sultry voice, Morgan mirroring his own words with rolls of the hips, pushing their erections together in a manner that left Spencer breathless and whimpering for more as he fisted the sheets beneath him.

"So just what are you planning on doing Pretty Boy?" Morgan drew, continuing the movement as Spencer arched and gasped, bucking upwards, desperate for more contact. "Because from where I'm sitting, it doesn't look like you're in much of a position to be doing anything."

And Spencer hated that Morgan was right because he wouldn't last long and he wanted so much more.

Spencer forced his eyes open because he didn't want to, because he couldn't miss a moment of this. The way Morgan looked on top of him, the unfamiliar weight pressing against him that just felt so right –

He choked back a cry as he felt the other's large hand coil around his aching length. He'd remember even the thick calluses on Morgan's hands, the rough edges that almost hurt against his sensitive flesh.

As his gaze flickered down to where Morgan's free hand gripped his hip to hold him down against the bed, he'd remember the stark and beautiful contrast between their skin.

"Not so cocky now," Morgan taunted as Spencer arched from the bed, and in Morgan's tone Spencer heard this for what it was: a game. Just a simple game to Morgan. A simple release. Nothing more.

And it hurt so much.

But how could he care when Morgan was fisting his dick, leaning over him and cooing, "I'm going to fuck you so hard you won't be able to move tomorrow."

Spencer licked his lips, staring up at the oh-so smug profiler before slowly nodding. "Please, Derek," he gasped, needing to feel what it was like, needing to know what he was never going to have again.

But Morgan arched a brow, a look of warning crossing his face, telling Spencer that he was dangerously close to ending this encounter. "Morgan," the older male corrected none too gently, and Spencer winced because he instantly understood his mistake.

First names were reserved for lovers.

And they weren't.

"Morgan," Spencer murmured in acknowledgement, a silent, it won't happen again, a silent plea for Morgan to not leave.

Morgan seemed unsure for a moment before that smirk returned and he replied, "Just this once, Pretty Boy."