You were washing your hands in the men's bathroom as Sherlock walked out of the stall he was in to wash his hands as well. You and him were flatmates, so you cheated a little, but he turned and saw a lady behind us. She seemed like a big fan of Sherlock, and her clothing was slightly... suggestive. Sherlock quickly deduced she was a news writer. You however did not. Sherlock spoke first. "Wrong toilet."