It started the night John found Sherlock in his bed.

It wasn't anything too strange. John figured that Sherlock was upstairs working, too lazy to make his way downstairs to his own bed and resigned to John's instead. Sherlock had been testing the reaction of plants fed with human blood (something that came about after he'd joined John halfway through watching Little Shop of Horrors the week before), and the light quality was apparently better from John's room. Either way – John came home from the surgery to find a rather dead looking plant in his window and a rather dead looking detective in his bed. Sherlock was sprawled out on the mattress haphazardly– dressing gown pooling around him like silky water, his trousers wrinkled around his calves and one slipper precariously slipping off his foot as it hung over the edge of the bed.

John thought about trying to move Sherlock, but with his awkward limbs and somewhat surprising weight, along with the long day that John had, the doctor didn't think he could make the effort that late in the night. He considered simply sleeping in Sherlock's bed – but on second thought he didn't want to venture to the other man's bedroom, afraid of what might be inside. His last options were the couch – which had given him an awful kink the last time he'd passed out on it – and simply sucking it up and joining the damned fool.

He mulled over the thought while he brushed his teeth, thought about it some more while he changed into pajamas and then took another minute standing at the foot of his bed simply staring at Sherlock, as if he was trying to will him awake and go to his own room. John finally resigned, figuring that there was enough room for both of them and he'd been in worse situations before. Certainly sharing a bed with Sherlock would be nothing like the dry heated battleground he'd spent so much time on, certainly.

It wasn't nearly as bad, but John couldn't say he had the easiest time getting to sleep. The strange angle in which Sherlock was sleeping – practically diagonal on the bed – made it difficult for John to figure out how to lay down. He eventually opted for a similar pose, farther up on the bed cushioned by all his pillows, parallel to Sherlock. His feet didn't hang from the bed if he drew his knees up.

The first hour was strange, he was worried that if he made any contact with Sherlock the other would surely bolt up and confuse his laziness and obstinacy for something else – but then he remember that this was Sherlock he was confusing with a normal being, with normal boundaries. Once he allowed himself to accept this fact he finally relaxed enough to drift asleep.

Around eight am he found himself awoken by the dull buzz of his cell phone, left in his trouser pocket the night before. He groaned and rubbed his eyes – staring at the ceiling. A light puff of air tickled across his neck and chest and he glanced down only somewhat surprised to find that Sherlock had managed to make his way to his side of the bed in the night. The lanky arms of the other man were wrapped around him like sloth, his leg bent up and slung across John's thighs, while his arms were across his chest. John thought a moment because there was something that wasn't quiet right about how comfortable he was with what was happening.

"Sherlock…" He whispered, groaning when he gained no response. "Sherlock." He said again, with a level and harsher tone. When there was still no response but the continuous dull hum of his phone John gave up and used all the force he could muster to fling the man off of him. Sherlock rolled back, his odd angle causing his body to slide off the bed in heap. John swore under his breath, sitting up to check to make sure Sherlock wasn't too damaged. He was startled by a mop of inky hair and Sherlock's half-asleep slurred words.

"How're the plants?" He asked, twisting around and looking at the window.

"Dead." John responded to him, sliding off the bed more eloquently and heading to his bathroom to splash his face with water.

"Perfect!" Sherlock exclaimed, visible in the doorway of the bathroom, locking eyes with John through the mirror.

"You're happy that they're dead, then?" John asked, putting a dollop of toothpaste onto his toothbrush.

"Yes, it was exactly what I predicted. The nutrients in human blood are not sufficient to sustain a common house plant – let alone produce some abnormal hybrid that is capable of speaking."

"Yes Sherlock, you have proven that the fictional circumstance of a nineteen-eighties musical are in fact: false." Sherlock looked at John with squinted eyes a moment before frowning and walking to inspect the plant further. John walked back into his bedroom, sliding off his shirt to begin changing, watching Sherlock and waiting for him to take the hint to leave – which he was of course completely oblivious to. "Sherlock." John said, unknotting his pajama bottoms. The slim man turned and looked at him expectantly before noticing his state of undress and pursing his lips in acknowledgement.

"Oh John, I certainly don't mind."

There wasn't much that made John think of the morning he found Sherlock clinging to him in the next few weeks. There were cases pouring into the Yard and both found themselves chasing crooks around the city – on the rare occasion where Sherlock could solve the cases from their living room, via the details given by Lestrade over the phone, John got to eat.

It was not one of those occasions however, when John and Sherlock stumbled up to their flat sweating and somewhat scuffed up from a fast chase through the city. John immediately walked to his room, turning on the shower and letting the bathroom fill with steam while he grabbed his clothes. He tossed his shirt aside, rolling his shoulder back into place with a satisfying click.

"Sherlock, grab my kit and come to my room so I can look at your shoulder." He called down the stairs before stepping into the shower and letting the heat of the water relax his muscles. Mid-way through rinsing the smog of London from his hair he heard Sherlock shuffle into his room and begin to prattle about.

"I don't think it needs examining." Sherlock said, his voice much closer than John expected, making John jump.

"Sherlock, honestly – I'm in the shower."

"Yes I can see that, hurry up or should I just jump in? It would be more practical, you can examine me in there." Sherlock was one step away from pulling away the frosted glass door before John grabbed it and it held tightly.

"No!" He shouted, letting out a breath. "Go sit on my bed, I'm almost done." He heard the shuffle of Sherlock's feet leave the bathroom, his figure seeping into the darkness of the bedroom. John finished washing and slipped into his pajamas before making his way into his bedroom. Sherlock was sitting on the edge of the bed, leafing through a book.

John took a moment to look at the gash he'd received on his shoulder blade – frowning at the torn fabric that flapped open revealing it. "Right," he said grabbing some anti-septic wipes and bandages, "take off your shirt – doesn't look too deep just needs to be cleaned." Sherlock nodded and made quick work of the buttons down his front, sliding the shirt gingerly over his wound. John dabbed at it softly – cleaning up the cut, wiping the red stain off Sherlock's cream skin. He spread some lotion over the cut and covered it with a bandage, feeling some pride in the goose bumps that spread across Sherlock's arms when he patted down the medical tap. His fingers gliding over his shoulder blade once more to make it flat.

The shower incident was never spoken of again, or suggested, and neither was the strange thickness that seemed to generate in the air after John finished patching up Sherlock's shoulder. He had to nudge the other man to get him to stand and go back to his own room – Sherlock playing it off as if he was contemplating something rather serious.

What couldn't be ignored though was the time in which Sherlock completely destroyed any miniscule boundary they had left – by completely invading John's personal space and making every elephant in the room trumpet loudly for both to see.

John had been sitting on the couch – flipping through trash television and wondering what else he could do with his day when Sherlock plopped himself down next to him. At first John didn't acknowledge his friend, but from the corner of his eye he noticed Sherlock was not looking anywhere near the screen – and instead had his eyes fixed directly on him. The doctor shifted uncomfortably and tried to ignore Sherlock, which became increasingly more difficult when he moved fluidly and was suddenly on top of him.

"Sher—" was about all John could manage to say before his mouth was otherwise occupied with the strange and yet not at all unwelcome feeling of warm pale lips against his own. Once the shock of what was happening faded, John noticed something strange about the way in which Sherlock was kissing him. He seemed to have a purpose in mind, his movements calculated and thought out. John did not appreciate this at all. If he was going to get snogged he wanted it to be a proper snog, not an experiment.

He pushed the detective back and reversed their positions – leaning over and pressing Sherlock against the arm of the couch. He sat back just enough to readjust himself, slide his palm against the smoothness of Sherlock's jaw, and look right into his pale questioning eyes before giving him a right proper snog.

Sherlock seemed intrigued by John's sudden change in behavior – letting the smaller man take over and explore, resting his hands against John's waist. When both were out of breath, John pulled away, resting his forehead against Sherlock's. His fingers were curled tightly in Sherlock's lapels, wrinkling the fabric mercilessly. Sherlock raised his hand and trace his lithe fingers along John's jaw, chin and lips – his eyes flickering about as he collected data.

"Interesting…" he mumbled.

"Don't do that." John warned, closing his eyes.

"John?"

"Don't you dare do that right now, Sherlock."

"Do what, exactly?" Sherlock tilted his head slightly, his curls falling to one side across his wrinkled forehead.

"Don't turn this into some kind of experiment – please don't tell me you just did that because of some hypothesis about human urges or some kind of bollocks like that. Because it bloody well didn't feel that way, and I certainly don't feel—I just don't appreciate being used like some guinea pig."

"You're not a guinea pig, John – this was a specific hypothesis I had, it needed to be proven wrong."

"Hypothesis… right." John drew out the word, pursing his lips and rubbing a hand over his face in frustration. "Do me a favor will you, stop using me for your bloody experiments!" He stood and up paced a few times mumbling under his breath before grabbing his jacket and storming down the stars – leaving Sherlock to deduce what he could.

When John came back it was dark and the flat was quiet. He glanced into the living room before heading to his own room, sliding off his jacket and tossing it onto the floor. It was when he sat on the foot of his bed and unlaced his shoes – letting them fall with a thud – that he noticed the mound of detective curled into his sheets. John rolled his eyes and looked at Sherlock – who was not sleeping at all, but staring at him from under his dark curls.

"John," he said simply, sitting up and letting the sheet pool around his waist.

"Sherlock." John responded. His voice was quiet and shaky – finding it hard to remember any of the things he had planned to say to Sherlock with the detective sitting in front of him.

"You're still upset." Sherlock stated, moving his hand across the space between them.

"Good deduction." John said coldly.

"But you don't want to be because you aren't upset about what happened… you're upset about why I did it." Sherlock said, his face twisting as he spoke his thoughts out loud. "You think I only wanted a reaction from you for some experiment, that I could have easily replaced you anyone and it was only because you were closest that I picked you as my subject."

"Well why else—"

"You'd be wrong." Sherlock said, cutting him off quickly. "If I wanted a reaction from anyone I would have picked someone with a simpler mind for a basic human reaction, perhaps Molly or Lestrade. But I didn't want that, I wanted specific information for my own personal query. It wasn't because I had an experiment in mind, it was because when I think of an idea my mind formulates a hypothesis first and makes it easier for me deduce everything properly." Sherlock spoke quickly, his voice trailing into itself like a long string of words and John found himself having to take a moment to realize what Sherlock had been saying.

"What was your query?" John managed, blinking a few times and pursing his lips.

"Whether or not you'd be willing to extend our relationship farther than it currently stands."

"Whether…" He screwed his face up slightly and ticked his head to the side, squinting his eyes. "And you tested this by attacking me?"

"No, not at first, that was simply the final trial. I initially slept in your bed, which didn't seem to offend you, so I administered another test – attempting to join you while you showered. Which of course resulted in your complete refusal. This could, however, be attributed to your shyness not necessarily because you were not interested in exploring a sexual relationship. Both of these attempts canceled out each other. I had to create a separate trial that would be the final determination."

"And that brings us to the snog-fest on the couch earlier."

"Yes, to put it less eloquently." Sherlock smirked just enough to wrinkle his cheek briefly, before letting the corner of his lip slide back.

"And what is your final deduction?" John said after letting the moment hang in the air.

"Why don't you tell me, doctor?"

John glanced over Sherlock's slim frame and smiled to himself, feeling a strange flutter in his stomach – which he was certainly too old to be experiencing still – and leaned over just enough to connect their lips.

Sherlock smirked against John's mouth, letting out a low chuckle. "What?" John asked, blushing slightly.

"My theory seems to have been correct..."

"Oh shut up, will you." John said rolling his eyes and making sure Sherlock couldn't say anything else for some time.