Haven't been in the Sherlock fandom for a bit, but I can't stop thinking about this.
After the Reichenbach fall, after Sherlock returns, John can't stop touching him. It's small touches here and there, a hand brushing lint and debris from his coat, or resting on his head briefly as John passes by Sherlock who's laid out on the couch. He leans more firmly into him, stands closer, holds his eyes for longer, hugs him more.
A person, who doesn't know their history, doesn't know about Sherlock's "death" or his second coming or how symbiotic Sherlock and John's relationship is, takes a fancy to Sherlock. They watch Sherlock and John interact. They observe all the little touches and how they keep increasing over time. They see the restlessness of Sherlock buzz under his skin as he forces his body to pause for however long John's touches last. Day by day, their jealousy heats into a boil until they want to scream.
One day they confront John right after his hand slides up to give Sherlock's neck a firm squeeze, his fingers twisting in his dark curls as they leave. The person asks, "Why do you touch him so much?"
And John, who's been doing most of his touching subconsciously and the rest of his touching under the assumption that he's been subtle, freezes.
Realizing they've struck a nerve, the person adds, with a vicious hiss underscoring their words, "Like you think he's yours or something."
John's eyebrows lower and his mouth twists. An expression carves itself on his face that makes him look pissed, but also like he might cry. His arms cross defensively and he masks taking a step away from Sherlock as a shuffling of feet.
Before anymore can be said, Sherlock, voice deep and eyes icy, says, "I am his."
Both John and the person look at him. John's head cocks as his glassy eyes widen and blink rapidly a few times. His lips press themselves into a purse and his crossed hands clench into the arms of his sweater.
"I consider it an observational fact which, if you had any sense at all in that vapid little skull of yours, you would have realized before opening your mouth and proving yourself a fool."
The person flinches back.
John's lips pinch in the corners the way they do when he's trying not to take ungodly glee in Sherlock's observations.
Sherlock delivers the final blow. "For as long as John Watson can stand me, in whatever way he wants me, I am his."
