[John's sleep is fitful at the best of times these days. Between Rosie and his ensuing depressive spiral and insomnia with Mary's loss at home, everything that is Norfinbury, and a natural propensity toward light sleeping from med school and the military, he's awake as soon as Sherlock takes a few steps in. He lies still, waiting to see what the other man will do for a few seconds before it becomes apparent what he's up to.

He rolls over to face the other man in the dark and his voice is quiet, steady.]

Sherlock, if you stop now and leave, I'm gonna pretend you just came looking for a midnight snack. If not, we're gonna need to have a talk. [That talk being 'stay the hell out of the drugs.']