Many had (have) tried to bring the great Sherlock Holmes to his knees. Assassins, thugs, Moriarty, Anderson - they had all wanted to win, wanted to see the detective bruised and battered, broken beyond recognition, ruined. Kneeling in tatters at their feet while they gloated over their victory. But the fact remained that as much as they had wanted it, they hadn't been able to do it. (No, the only person with that kind of power over Sherlock is Sherlock himself, and John somehow manages to find this more worrying than the preserved human fingers in his favourite teacup the week before-)
And John Watson knows it's a little immature and more than a little unreasonable, but he can't help feeling selfishly proud that he'd managed to do what desperate criminals and malicious masterminds and intellectually inferior policemen had failed to - bring the great detective to his knees. Literally.
And wasn't it delightful the way the taller man was currently kneeling between John's widely spread legs, lavishing attention on the proof of the doctor having less than pure thoughts about his roommate? Oh, oh, just like that, John though when that clever, clever tongue flicked just so, and he could actually feel himself getting closer to the edge. Strange, that - Sherlock usually (surprisingly) liked to take things slow, keeping John aroused but far from sated for hours at a time before finally deigning to make him come. It kept the detective distracted during the harrowing times that cases were few and far between, but didn't- Sherlock took John's length down to the root and then swallowed around it once, twice. He must've really wanted the doctor to come. John idly wondered why. The last time Sherlock had done something like this, there had been a rotting corpse in their bathroom and a mad killer on the loose (wasn't there always?), and they'd ended up being chastised by Inspector Lestrade for indecent exposure. God, that wasn't the case this time, was it? John really didn't want to have another talk with the long-suffering Inspector about why, exactly, dark alleys close to crime scenes weren't the best place to be caught trying to-
Sherlock suddenly stopped his ministration, unsurprisingly aware of the other man's distracted demeanor. Or his flagging... interest. What? Thinking about getting caught (or cleaning after the rotting corpse in the bathtub) again wasn't really conductive to staying aroused and-
"Why, dear Watson, if you're not going to pay attention to what I'm trying to do here, we might as well stop," the detective said in a biting voice which did nothing to disguise his annoyance at the former soldier. As impassive and uncaring as the tall and slender man appeared to others, the doctor was terribly aware just how selfish and envious he could become in order to gain his attention. And gain it he did, either through his brilliant reasoning or through some other, less than noble means. John wasn't complaining, either way.
"Oh, I wouldn't dream of stopping you," replied the doctor in a voice that tried to be pacifying but ended up doing the exact opposite. Teasing Sherlock Holmes might not have been the smartest thing the doctor had ever done, but sometimes the temptation proved itself to be too much for him to resist.
"And yet if your thoughts continue to deviate so persistently from our more... pleasurable goals, that is exactly what will happen," Sherlock answered with a somewhat mocking, somewhat condescending and more than just somewhat irritated tone.
"And pray tell, how come you are so confident that my attention is not focused solely on you?"
The flat look sent John's way was a clear indication of just what Sherlock thought about the doctor's attempt at playing dumb.
"Unfortunately for you, I have yet to go blind, deaf and dumb. However, if you would be so kind as to share your enrapturing thoughts...?" the detective asked, unamused, even as he slowly dragged his fingertips along John's inner thighs, scratching lightly, the way he knew John liked. The moan that escaped the doctor was all the proof Sherlock needed to know the other's preferences hadn't changed overnight.
Of course, the dear doctor could have answered the question truthfully, but that would have most likely ended in a sarcastic reply and a sharp verbal jab at his ego.
"What, does the great Sherlock Holmes have trouble guessing my thoughts?" was the mocking and deflective question.
"As I have reminded you countless times before, I do not guess. I observe and I analyse and I deduct, and I'll have you know that guesswork has nothing to do with it," the detective spat. He continued after a short yet spiteful pause. "And I'm afraid that as well versed as I am in body language and psychology, I am still unable to read thoughts."
The conversation was starting to go sour, the doctor realised, and tried to divert the detective's attention back to its original... train of thought, as it were.
"Oh, well, since you seem so curious about my thoughts why don't I show you? I'm sure you'll find them very... intriguing," said John with a mirthful voice and a smoldering look, lifting his lover in his lap to kiss him and then proceeding to let him know just what he had been thinking about.
And maybe it wasn't what Sherlock had meant, but having the great detective on his knees was as good as having him in your lap or taking him from behind, and John Watson had never been a very picky person when it came to that. Besides, it appeared that catching the eye of the great Sherlock Holmes was quite entertaining indeed, be he on his knees or not. As long as you didn't let him get distracted.