Sherlock leapt to his feet and threw himself across the room at John in a passionate embrace. Sherlock's mouth locked onto John's in a kiss, that left John spluttering and struggling for air. When Sherlock finally let go his armlock, John staggered backwards in shock.
John rubbed around his mouth with the back of his hand - and then again with the other hand, for good measure. "What in the name of Lestrade and our friend, Molly, did you do that for?" he stuttered. *
Sherlock was looking both slightly pleased with himself and also a little defensive.
"I did it for you," he said, in the superior voice of one bestowing a precious gift that had been badly received.
"I'm not gay, I keep telling you, and anyone else who'll listen, anyone who will actually listen, that I'm not gay."
"Exactly!" Sherlock said, with a smug tone.
"What do you mean?" John looked non-plussed. "And that - for the record - was disgusting!"
Sherlock remained stalwart to his actions. "I did it so that you could get that out of your system and, judging by your reaction, I achieved what I set out to achieve. A highly successful mission, accomplished."
"What? What do you mean, Sherlock?"
"That I saw you staring at me, wondering whether all the talk is justified, and whether you really do want me in that way."
"I was thinking nothing of the sort - what on earth drew you to that erroneous conclusion?"
"Your eyes were dilated-"
"It's dark in here! Those blinking energy saving lights take half a day to get bright enough to see by."
"Your heart rate was elevated-"
"I'm recovering from a bug and a low grade fever, and having just cooked us dinner - that or starve - has rather taken its toll!"
"You were eyeing me up-"
"I was wondering what it was caught in between your teeth ... spinach, I believe, given what we've just eaten."
Sherlock was still looking rather haughty.
"Did you have to be quite so ... er, passionate?" John complained after a short silence.
"No point in going in half-hearted," Sherlock confessed, "Or you'd not believe that I meant it, and the point of the thing would be lost. You had to be certain it was no go."
"For goodness sake, Sherlock," John said, exasperated. "Ask - ask what people are thinking and feeling, especially in relation to you." John leant over to reach the box of tissues, his nose was running again. "That was truly gross, Sherlock. I get a mouthful of secondhand spinach and manage to unwittingly share a considerable amount of mucus in exchange -gross!" He sneezed loudly, as if to prove a point.
While John had been reaching for the tissues, Sherlock had bent over his microscope again and didn't appear to be listening anymore. John shrugged his shoulders and blew his nose with as much force as he was able. "Hurmn?" Sherlock mumbled, without looking up.
* John's version of 'the saints and all that is Holy'.