Knowing When To Leave

A man walks into a bar and asks for a beer. After drinking it, he looks in his shirt pocket and asks for another beer. After drinking that one, he looks in his shirt pocket again and asks for another beer.

This happens about another seven times before the curious bartender asks him, "Every time you order a beer, you look in your shirt pocket, why?"

The man replies, "I have a picture of my wife in there. When she starts to look good, I'll go home."