A chap I know had arranged to take a girl out. He was on his way to see her when he saw her father, whom he knew slightly lurking in the street outside with what looked like a baseball bat under his coat. He politely greeted him and asked what he was doing.
"My daughter's fixed up to see some dirty bastard with a nasty reputation for shagging and chucking, so I'm waiting until he turns up to give him a very strong message."