The way John finds out that Sherlock wants to marry him is he catches him practising rambling, nervous proposals to Billy the skull.
"Right, how does this one sound? ’John, you are not the most clever person in the room, but without you I wouldn’t be half the man I was. Will you marry me?’ …. no, you’re right, that probably isn’t good… Okay, uh, what about this one? ‘I think we can both say your marriage to Mary was a bit of a disaster, but I can assure you that marriage to me won’t be. After all, I won’t shoot your best friend in the heart. Well, your best friend is me, so that would be suicide.. so I’m saying I won’t….kill myself… marry me?’ Well, that one started out well enough….”
John listens to this go on for well over 10 minutes, biting his lip to keep from laughing. Finally, from his eavesdropping spot, he says “Yes”, walking up to Sherlock and holding his face in his hands.
Sherlock blinks a few times, “What?” he says, completely dumbfounded.
"Yes, I will marry you, you git!" John replies with a laugh.
Sherlock’s face goes deep red, his pale eyes turning away in embarrassment, “Oh, so you heard that, did you…?”
John nods, smirking in amusement. ”Yeah, I did. You are REALLY bad at this!”
Sherlock opens his mouth to protest but is cut off with a lingering kiss and suddenly the words don’t matter. All that matters is the result.
( sherlvckhomo, princessbottomlock, anotherwellkeptsecret, johnlockery, aconissa, justsuperblue, trickortrevor)