I just had this cracktastic thought: Sherlock comes up to Molly and says "Good news! My deduction that your boyfriend is gay was wrong!" and Molly barely has the time to look relieved before Sherlock continues "Bad news: he's a criminal mastermind and has only used you." and Molly looks like "GODDAMMIT, SHERLOCK!" while John facepalms at Sherlock's insensitivity.