One day a bachelor, who was a poor tipper, walked into his favorite restaurant and ordered lunch. A new waitress served his meal and received a three cent tip.
When he came in the next day, she thanked him for his 'generosity' and she said she could tell the character of a diner by the way he tipped. "Yea? What can you tell about me?" he asked.
"You put three pennies in a neat row," said the waitress, "and that shows you are a very tidy person. The first penny tells me you are frugal and the second tells me that you are a bachelor."
"That's true," he agreed. "But what does the third penny tell you?"
"The third penny tells me your dad was a bachelor too!"