A/N: Just some smut, for smut's sake :) I've always enjoyed the image of Reid being rimmed, but there's not nearly enough fics on it.

Disclaimer: Unfortunately, I do not own Criminal Minds or any of its characters.

All of Spencer's world at the moment was Derek.

More specifically, Derek's mouth. On him. Back there.

Derek had been wanting to do this for the longest, but when he saw his pretty boy walk in the bullpen with those tight ass pants on, walking around, and making sure everytime he bent down, his ass was in perfect view of Derek, the older man made himself promise that later on back home the genius would get devoured.

Derek had stripped both of them of clothes, afterwards making Reid get on all fours, the younger man slightly displeased with the rushed feel.

All of that slowly disappeared once Derek's lips hit his neck, kissing down to his shoulder, and down across his back. His hot tongue ran up and down his spine, causing tiny goosebumps to pop up over Spencer's body. After a few more moments of that, Reid was pressing back against Morgan.

Derek's chuckle made Spencer's body vibrate, and was in a neutral state, until he felt Derek's teeth on his ass.

His breath hitched.

"Uh, um, Derek?" he tried.

"Yes, baby?"

"What... what are you doing?"

"I haven't done anything yet."

Reid couldn't argue that, and could do nothing but wait. Derek was kissing all over his backside, kneading Spencer's ass in his hands. Reid started to let himself relax to the sensation, but the feeling was quickly lost as he felt a wet tongue prodding his entrance.

Spencer reached up to grab Morgan's arm, breathing strangely due to the foreign invasion. "Derek..." he gasped.

Morgan began lapping at the sensitive flesh, the pace of his tongue speeding up and slowing down. Reid's body was making some funny movements, pushing back and pushing forward as if he wasn't sure he liked this or not.

Once the older man could feel Spencer loosen up, he allowed his lust to control him. He held the trembling, pale hips in front of him to prevent him from moving, and buried his face inside, passionately making out with Reid's hole.

"Oh God... Fuck... Derek, I-" Spencer tightened his hold on Derek's arm, his breaths rapid and choppy.

Derek got on his knees, and Spread Spencer's legs wider. He started licking at it like it was a delicious ice cream cone, quickly melting in the sun. Spencer was gasping and moaning, and was struggling to keep himself upright. Doing this to Spencer was mindblowing, sexy, one of the most erotic things Derek could remember doing. The most. Spencer's arms soon gave out.

This of course gave Derek better access.

"You're so hot... so responsive. You have no idea..." Flick. "...how much-" Flick. "...I like doing this."

The younger man screamed in the pillow, his hips uncontrollably pressing back against Derek's mouth. "Don't stop... Please."

Reid was in absolute, tingling bliss. It was perfect. Derek's lips on him like that, his tongue moving like that, talking against it, oh god. It was so wet, so good...

Morgan was harder than he had ever been, and every time Reid's hole twitched when he ran over it, he got a little harder. He stopped Spencer when he noticed his hand reaching down to touch himself.

The sound Reid made was bordering on a sob, but Derek wanted to be the one to trigger his release.

He moved back, and stuck one of his fingers in his mouth before entering Spencer with the wet digit.

"Derek..."

Spencer couldn't stop moving. He believed if he didn't get release soon his brain would explode, ignoring the random facts and myths that popped into his brain at the subject.

Derek was moving his finger agonizingly slow, stroking Reid's arousal at the same pace.

And just when Reid was about to yell of frustration, Morgan was fucking him, hard. And deep.

The older man heard nothing from Reid for just a moment, and every sound he had every possibly held in from the previous 35 minutes exploded out of him as he felt Morgan's hips slamming against his. Derek held onto Reid's waist, his free hand reaching under to stroke Reid's leaking cock, whispering words driven from arousal against Reid's ear.

"That feel good, baby?"

Reid had long ago lost the ability to think, not about anything but the intense pleasure his body was in. Morgan was repeatedely brushing against the nerves deep inside him, as well as running his fingers along his hardness.

Derek changed the angle, lifting Spencer up so they were both on their knees, the pauses between their thrusts getting farther, and farther between.

"Oh, oh, oh, oh, yes...Derek, Derek!" Spencer bucked his hips into Derek's hand, his nails digging in the panting male's wrist, seconds away from release.

The hand on his cock moved faster, and Spencer's entire body stilled. The pleasure was blinding, and the young genius never wanted to come so bad. He wrapped his arms around Derek's neck, tilting his head back into his chest and screamed. His body jerked and his muscles clenched so hard around Derek he came almost instantly, shuddering and whispering Spencer's name.

Reid's orgasm was long and hard, his body continuing to shake long after Derek's release. He held the younger man through the violent tremors, kissing the tears off of his face, and waited until his breathing returned to normal.

They showered and didn't bother to wear anything to bed. Sleep came to them both as easily as breathing.

A/N: You're welcome.