The Devil in a Packed Bar

The Devil walks into a packed bar. Once people noticed the devil, the bar emptied with people running out the door screaming for help. Every one ran out except for one middle aged man sitting at the bar. The Devil walks over to where the man is seated and says "Don't you know I'm the Devil?"

The man sitting at the bar took another sip of his drink and says, "I know who you are."

The Devil shook his head at the man and said, "Well aren't you scared?"

The man looks at the Devil and shrugs "No, I've been married to your sister for 23 years. Why would I be scared of you?"
Source: Alcoholic Humor