Sherlock watched John go into the loo and close the door. He had no idea what the protocol was now. Was he supposed to join John in the shower, or just wait here until he was done? All of his other shags were a fuck and then gone. There was no lingering, there was no talking, and there was certainly no showering afterwards.

He looked down at himself, he was a bit of a mess himself. One quick sweep of his fingers would get him clean, but then how would he explain that to John?

Sherlock sighed, and decided that staying slightly messy and naked was preferable to dirtying the only pair of clothes that he had with him.

So he slumped down on the couch and waited for John, trying to occupy his mind so he didn't die of boredom first

Not that he actually COULD die, but he was sure he was going to if the man took too long.