A/N: It feels angsty at first, but I promise you it doesn't last long. It's been a while since I've written anything even remotely resembling smut so please bear with me. Actually it's been a while since I've written anything at all, so I sort of forget how to do endings. :3

"SHERLOCK!" Sherlock Holmes opened his eyes as he was ripped from his stream of consciousness. "Blast," he thought. "He's found it." He shut his eyes again just as a very angry John Watson came storming into the living room.

"Don't even pretend to be asleep, you wanker!" he shouted as he threw open the blinds.

"Are you angry with me, John?" Sherlock asked, not stirring from his supine position on the sofa.

"I am a hell of a lot more than angry with you, Sherlock. This is the last straw. What the HELL have you done to my bedroom?" The doctor was positively foaming at the mouth.

"Experiment," Sherlock muttered through tight lips. He believed John was overreacting and perhaps he would forget about it all in a few hours.

"Experiment? You have the whole bloody kitchen for your experiments! Why in hell do you need my bedroom?"

"Your room receives the most ideal amount of sunlight for the longest amount of time," he glanced at John for a moment before returning his eyes to darkness. "Sunlight is vital to the experiment."

"You know what? Fine!" John stormed around the room, gathering loose items that belonged to him. "Use the whole bloody flat for your damned experiments because I can't take this any longer. I'm leaving, Sherlock! Do you hear me? It's too much!"

"Who do you think is going to suffer more, John? Hm? You or I?" Sherlock whipped himself up from the sofa in lightening speed. He was face to face with John, who had stopped dead. "If you leave I'll just continue my work without you. You are expendable, John. But you, what will you do? Probably stay with Sarah until you can find permanent lodgings. You'll work in your monotonous job by day and sit in your home by night. You are an adrenaline junkie – that is no secret. You'll be cut off from your drug of choice. Your limp will resurface, no doubt. Now I ask you again: who do you think is going to suffer more?" He spat his last sentence as if it had a bad taste. He stood rigid, looking down upon the doctor, his fists clenched at his sides, terrified of John's final decision, but he could never let that show.

"Fuck you," John said softly at first before repeating it with rage. "Fuck you! You're full of horseshit, d'you know that? You wouldn't survive without me. Mrs. Hudson would find you dead on the floor within a week, starved or drugged or who the fuck knows. You need me. You need someone to take care of you. Even more than that, you need someone to talk to, to bounce ideas off of! Your cases would rot on the table without me as your lab rat. So now, if you don't mind, I refuse to accept any more of your abuse. I'm leaving. I'll get my things another time. I just can't deal with this shit anymore." John stared into Sherlock's eyes, pausing before he left. The taller man's face conveyed an emotion that John could not quite decipher. It was a miracle in itself to see some shred of feeling on that face. He turned to leave, swallowing the sense of sadness that was creeping up his throat. Before he could walk more than a step he felt a strong grip on his wrist. Suddenly he found himself chest to chest with Sherlock.

"Don't leave," said the detective with a barely audible whisper. Then he violently pressed his lips to the other man's mouth, pulling him in by the waist. John stood paralyzed for a moment, unsure of what to do. On one hand he had just decided to forever free himself of the madness that is Sherlock Holmes; on the other hand, however, the same Sherlock Holmes was exploring his back with his strong, powerful hands, completely uninhibited and fuck it felt good. For months he had had dreams that went a little like this, but he never imagined it ever actually happening. Finally he gave up all resistance and slid his hands around the thin man's waist. He parted his lips and allowed Sherlock's eager tongue to enter his mouth while he himself pulled Sherlock's hips as close to him as possible. He could feel Sherlock through his pants and this sent a devilish tingle down his spine. Sherlock continued to explore the inside of John's mouth, and when that quickly began to bore him, he bit and tugged on the doctor's lower lip.

"Fuck, Sherlock" he breathed.

"Still thinking about leaving?"

"I don't know, I might need a better incentive to stay." The words had hardly escaped his mouth before Sherlock backed him hard into the wall and slid a knee between John's legs. When John failed at suppressing a moan, the other man took the opportunity to lick the inside of his mouth and the back of his teeth. He tugged again on John's lip before moving down to his jawbone, and then the soft, exposed side of his neck. John's fingers found themselves tangled in the thick mass of curly hair that was before them. Sherlock kissed his neck tenderly, licked a line straight up from his collarbone, and then began nibbling on his earlobe. The detective had taken note early on that his new partner responded well to the sensation of teeth nipping his skin. As he continued to kiss and suck his partner's neck, his hand traveled down to John's pelvis. He lightly applied pressure to the tight region of his trousers and John responded by moaning and pushing into his palm.

"How long?" he said as pale, spindly fingers began to work their way underneath his jumper.

"How long what?" Sherlock asked. "How long have I wanted to do this, or how long have I known you wanted it as well?" He splayed his one hand across John's still surprisingly toned abdomen as the other continued to palm at his erection.

"Both."

"Since shortly after we met, and about a month after that. It wasn't too difficult to deduce. You either abstained completely from touching me in any way, or you went out of the way to display the slightest touch. After walking in on me while changing you became flustered, even though I am sure you had plenty of experience seeing men change their clothing during your time in Afghanistan. Besides those more outwardly clues, you become slightly flushed in my presence and your pupils would dilate." John had begun to push them away from the wall and towards Sherlock's bedroom door as the deductions were listed.

"Oh," Sherlock added as he fumbled the door open, "and one night I heard you utter my name as you masturbated." John stared in horror as Sherlock winked at him and sat onto the bed, pulling the shorter man onto his lap.

"I didn't – I'm sorry you – oh fuck," he mumbled.

"It's quite alright," laughed the other, flipping his dark hair out of his face. "I actually became quite aroused." John climbed more onto Sherlock's hips, straddling him, growing more confident after what had just been said.

"Really?" he asked while roughly attacking those pink, thin lips.

"Oh yes. I love hearing you say my name when you're all hot and bothered."

"Oh," John moaned teasingly as he rotated his hips, "Sherlock." He watched as Sherlock parted his lips slightly and closed his eyes, his breath becoming slightly erratic. To see him in such a state just made him want more, and Sherlock seemed to, as always, read his mind. He ran his cold hands under John's jumper and up his bare back before removing the article altogether. He grabbed the other man's muscular thighs and tilted him backwards onto the bed before straddling his hips and pinning him down. He leaned down to kiss and lick the soft skin of John's neck, collarbone, chest, nipples, and finally his navel and lower abdomen. John squirmed, desperately wanting to be released from the confines of his now uncomfortably tight trousers. Sherlock noticed this, began to unbutton the offending pants, and pushed his hips down in a circular motion. The two cried out in unison, although Sherlock had not meant to.

"There's more of this if you promise to stay here," Sherlock whispered into John's ear. John shuddered with delight.

"I'll only promise if you promise."

"Fine, I promise," Sherlock smirked and reached his hand down the front of John's pants. John gasped and wondered to himself how just a few short minutes ago he had seriously considered walking out over a silly experiment, and how this experiment would completely change his mind.