Pants on Fire
The first time it happens, Sherlock is fourteen. He wakes to find a small scorch-mark on his pants. Further investigation reveals a matching burn on his sheet.
How did they get there? Sherlock has no memory of using matches, a lighter, or flames of any sort before bed. Had he gotten up and set something on fire in his sleep?
Scanning back through his dreams, Sherlock recalls a particularly vivid sensation of being aroused. Sexually. He flashes back to a health class in which the teacher mentioned wet dreams. But this seems to have been the opposite of a wet dream.
Sherlock stares down at his penis, flaccid and harmless-looking. He knows that people sometimes refer to sex as being "hot," but he's never heard of a nocturnal emission leaving scorch marks. The term "seminal fluid" had led him to believe that semen would be liquid.
Well, there's one way to find out. Though he's never been tempted to try it before, Sherlock decides that he'll have to masturbate. For science.
The results are shocking. At the point of climax, a thin stream of fire shoots from the tip of his penis. A few sparks fall to the floor, smouldering briefly on the carpet before going out. What the hell was that?!
Over the course of the next several months, Sherlock does all the research he can, both practical and theoretical. Nothing he can find online bears any resemblance to his own experience. There's only one logical conclusion: Sherlock is a freak.
By this time, his parents have begun to notice the scorch marks. They chastise Sherlock for conducting experiments in his room, when they've set up a perfectly good laboratory for him downstairs. Mummy questions him about the damage to his clothing.
Sherlock puts her off with a story about an experiment on the flame retardant properties of various fabrics he's conducting for a school project. As the words leave his mouth, he can hear Mycroft's voice in his head, taunting, "Liar, liar, pants on fire…"
Soon after that, Sherlock makes a decision. The risks — of exposure, of burning down the house, of being locked away in some secret government testing facility — aren't worth it. Better to take sex completely out of the equation.
Sherlock learns how to will away erections. He begins staying awake for days on end, so that by the time he does fall asleep his body is so exhausted that there is no chance of a wet (or, rather, fiery) dream. He avoids forming any sort of relationship that could possibly lead to attraction.
So this is how Sherlock grows up: isolated and lonely, but safe. And then he meets John.
When they go out to dinner at Angelo's, and John asks if he has a boyfriend, Sherlock is momentarily stunned by his body's response. The mere thought of it, coupled with the sight of John's pink tongue poking out to lick his lips, has Sherlock's cock hardening uncomfortably in his pants. Oh, how tempted he feels.
But it could never work. Sherlock's arousal is a dangerous thing, and must be ruthlessly tamped down. So he forces himself to tell John that he is married to his work.
This time, it is his own voice he hears in his head, mocking him. "Liar, liar, pants on fire…"
It's worth it, though. Sherlock is keeping John safe. Sherlock is keeping John. And it's worth it.
As the months and then years pass, Sherlock's attraction to John only grows, but so does his determination not to do anything that could hurt the man who has become his best friend. Although he's too observant to have failed to notice that John reciprocates his interest, he is sure that it is better for John to experience a bit of pining rather than suffer severe burns. And, less altruistically, Sherlock is unwilling to risk making a move that could end in John leaving him.
Then, one day, everything changes.
Sherlock's latest case has brought him and John to a circus. This is the third time, in fact, that they've visited a circus together, but the first time the circus features fire-eaters. Sherlock is watching, transfixed, when John casually mentions that he dated a girl in uni who knew how to swallow flames safely, and she taught him the trick.
Suddenly, the case is forgotten. Sherlock drags John back to Baker Street without an explanation. Something in his manner cues John in to his intention, though, and the moment they're in the flat they're kissing.
As they break apart for air, John gasps out, "Finally! I thought I was going to spontaneously combust before you got your head out of your arse! What took you so long?"
Sherlock glances down at his obvious erection, and John follows his gaze.
"Can I show you something?" Sherlock asks.
"Oh, god, yes!"
End Note: Come on, baby, light my fire with your reviews. )