LOL Dick Cavett (the well known American talkshow host of the 80s) told a story about having a guest come out and reveal to him but not the audience that his fly was wide open. He knew that all the guest had to do was sit down in the open format swivel chairs and pivot his chair and be 'revealed' so he quickly said "let's play a game before you sit down. Do everything I do..." he put his back to the audience and bent his elbows and said: "One of us has our fly unzipped. We're going to go through the motions and then sit down and chat!"