Sherlock is convinced that he did something wrong. Nothing terrible, just one of those things that John never knows how to address, because he doesn’t want to hurt Sherlock but can’t let go either.
“John. Stop lurking in the door frame and just say it.”
Feigning ignorance. Really, John?
“You’ve been hovering around me for the last 38 minutes, clearly there’s something on your mind. Let’s just hear it and get it over with.”
Too harsh? He wants to annoy John enough to say it, but he doesn’t want to hurt him after all.
Then John blushes.
Something doesn’t add up. John rarely blushes. Something sexual then? Did he manage to hide a strange kink from Sherlock? Like...
Before Sherlock’s brain can come up with something shocking enough for John to be blushing (because John is not shy when it comes to asking for something in bed), John starts speaking.
He still looks uncomfortable but Sherlock asked and he is not someone to back down, no matter the degree of uneasiness.
“Would you play the violin for me?”
Sherlock stares at him. He usually plays the violin because it helps him think or because there are feelings to deal with. Or to annoy Mycroft. Never for others. He never wanted to. Until John asked.
He smiles and lifts the bow.