ummm... RTYI? I do this in my fic (Plausible Deniability http://archiveofourown.org/works/1158324?view_full_work=true), but I'm not sure what else you're looking for, story-wise. Oh and in another one of mine too, actually, but that's an entirely different context and John knows. mycroft says no dice. ok ok so maybe its not what OP wanted?