John awoke with a raging hard-on and an urge to jump up and grab for his gun. He lay still for a moment, instead, sorting out which of the two reactions was from his dream and which wasn't. Not that he could remember what the dream had been about, exactly, but it was warm and inviting and - okay, yeah, that explained the morning wood. He stayed frozen for several seconds and held his breath. Still a strange feeling that something wasn't right, but there was no movement and no sound from elsewhere in the flat. Sherlock was out, then, or still sulking in his room. (Highly unlikely he was sleeping - the man was practically a damn vampire.) John let out a long sigh and tossed back the covers.

Morning wanks weren't exactly unusual - not every day, obviously, but John allowed himself the luxury more often than not. Especially when he had actually slept well (true today) and he didn't have to be anywhere for a good while (ditto). He dipped his hand under the waistband of his pajama pants and tugged gently, working himself up the rest of the way. He was almost out of lube - probably enough left for one or two more sessions, but after that he'd definitely have to make sure -

Some tiny bit of motion caught John's eye, and he froze again. It only took a moment for his army-trained reflexes to sort it out - a flash of pale skin in the mirror. Someone standing just outside his door on the upstairs landing, trying not to be noticed. John glanced at the mirror with his peripheral vision again, trying not to make it obvious he had seen anything, and was rewarded with that same flash of white -

Sherlock. John was rather pleased to realize he could identify him purely by a half-inch stripe of light on his cheekbone, actually. He was lurking behind the half-open door, nearly completely hidden in the dark, but a bit of morning sunlight had filtered through the crack of the doorhinges and was illuminating a tiny portion of his face.

John's instinctive response - jumping out of bed and demanding Sherlock explain what the hell he thought he was doing skulking around the flat and watching John sleep - was almost immediately overwhelmed by the realization that Sherlock had seen him lazily jerking himself off. John had thrown back the covers first - nothing to stop Sherlock from peeking through that narrow crack and observing him while he wanked. And yet he was still there. John carefully stretched and rolled, turning away from the mirror before Sherlock noticed he had been seen.

What was Sherlock after? It was entirely possible this was part of some experiment - John had long since given up on convincing Sherlock to stop conducting experiments without his consent. Their current agreement, after much yelling and "negotiation," was more along the lines of "Sherlock may not experiment on John, unless John says it's okay or he wouldn't mind anyway or he won't notice or Sherlock is able to get away with John never finding out what the real story was." It wasn't a perfect compromise, but it was livable - like so many aspects of living with Sherlock, John had been forced to either compromise or just give up. At least compromising was progress.

But did it really matter what the experiment was? Sherlock watching him sleep was a bit creepy, no matter what the circumstances. And now that he was awake, obviously inclined to engage in a bit of private time, and Sherlock still hadn't left . . .

An idea appeared, slowly but surely building up steam. John so rarely got to put one over on Sherlock - it wouldn't last, of course, but perhaps it would be fun to get one-up again.

Before he even really had a chance to think it through, John had made up his mind to go for it. He rolled back to his back and stared up at the ceiling. He had to force himself not to glance at the mirror or the door, but it wouldn't do for Sherlock to know -

"Mmmmm." He palmed himself again, bringing a little jolt to his nerves and a noticeable change in status to his erection. It wouldn't do to be too dramatic, but he wanted Sherlock to get an eyeful - so the key had to be a careful balance between theater and his regular routine. John tugged his pajamas and pants down to his hips - he didn't usually bother undressing for this, but since he had an audience . . .

There was a tiny noise from behind the door, quickly silenced. John pretended not to notice. It helped, oddly enough - he'd never thought himself that much of an exhibitionist, but knowing Sherlock was watching was absolutely in the plus instead of the minus column when it came to inciting his libido. Strange. And definitely something he wasn't ready to examine all that closely.

He let his head sink into his pillow and he closed his eyes. Slow, steady strokes, just enough to get his cock interested but not enough to require more attention - not yet. He paused just long enough to locate the lube in the bedside table drawer by feel - he was indeed almost out, judging by the weight. There was enough left for a generous dollop on his palm though, and oh, perfect. It warmed up quickly and soon his hand was nearly frictionless as it worked its way up and down.

"Yes," John mumbled. He wasn't normally a talker (or mumbler or crier or much of anything else, really) when masturbating, but this was payback for Sherlock spying on him. "Oh, God, please. Your tongue is so - fuck."

It might have been John's imagination, but he would have sworn he heard Sherlock shift his weight on the other side of the door.

John kept his hand moving steadily, even as he slid his other hand upward under his shirt to rub over one nipple. Which was definitely peaked and ready for the attention. "Christ," he muttered a little louder. "Want you to - mmmmmfff. Like that." The groan that escaped his lips wasn't entirely feigned. "Fuck, Sherlock, you've got the most luscious mouth."

Now it definitely wasn't his imagination - Sherlock shifted and froze. John didn't dare open his eyes, supposedly caught up in the fantasy as he was, but he could picture it perfectly - Sherlock peering through the crack in the door, knowing what he was doing was A Bit Not Good, but helpless to look away. And then seeing John shuck his pants, start stroking himself off and moaning. And then calling Sherlock by name. In John's mind's eye, Sherlock's face was frozen in shock, his eyes wide and eyebrows raised, his mouth open helplessly. John squeezed his eyes shut tighter and envisioned fucking that delightfully open mouth.

And hell if that little mental image didn't help. John quickened his pace, no longer caring if he was making noise incidentally or intentionally. In his mind, imaginary-Sherlock was on his knees in front of John, hands on John's hips. His mouth was stretched around John's cock, taking as much of it as he could fit, but his eyes were locked on John's. They were practically burning in their intensity, the clear message fuck me fuck me fuck my mouth coming across loud and clear even as Sherlock's mouth was otherwise occupied. John groaned aloud and squeezed his fingers a little tighter, adding a bit of a twist to the foreskin as his hand reached the tip.

"Oh God, Sherlock, I'm gonna - I'm gonna -" He shuddered and gasped as the wave swept over him. His hand caught the brunt of the mess, but judging from the slight shift in weight and temperature against his abdomen, his pajama shirt was a lost cause as well. John sighed and let himself lie boneless against his mattress for a long moment.

That . . . wasn't supposed to have happened. He had planned to call out Sherlock's name, sure, but not to actually wank to images of Sherlock sucking him off. John spent a few seconds wondering why the idea had appealed to him in the first place - he was straight, damn it! - but more than that, he really wanted to just clean off and go hop in the shower.

And getting up immediately meant he got to confront Sherlock now, before he had a chance to recover and come up with a plausible lie (or to pretend he had never seen anything at all). John sat up, stripped his pajamas and pants completely off, and quickly threw on a t-shirt and a fresh pair of comfortable trousers just like he always wore to come downstairs in the morning. He threw open his bedroom door like he didn't know Sherlock was behind it.

"Ow."

It didn't open all the way, of course, just bounced off Sherlock's body and settled in at a forty-five degree angle. John stepped through it and put on his best military frown.

"Sherlock?"

Sherlock at least had the sense to look a bit embarrassed. "I was, ah, just coming up to see if you were awake yet."

John blinked at him. "You usually just yell up the stairs."

"You hate it when I do that."

He took a deep breath. "How long were you here, exactly? Were you watching me?"

Sherlock's eyes slid away too quickly. "No, I didn't see - I was just about to knock."

"I didn't hear you on the stairs."

"I . . ." Sherlock swallowed.

"Be careful, Sherlock," John warned. "If I were to notice you were doing something like spying on me in my sleep, I might be forced to make a big deal about it. You promised not to experiment on me anymore."

"I wasn't," Sherlock said, voice tight.

"Make sure it stays that way." John brushed past him and started down the stairs. "Besides, you never know what you might wish you hadn't seen."