"What You Leave" joke

A old man stops by a cafe for breakfast. After paying the tab, he checks his pockets and leaves three pennies for a tip.

As he strides toward the door, his waitress muses, only half to herself, "You know, you can tell a lot about a man by the tip he leaves."

The old man turns around, curiosity getting the better of him. "Oh, really? Tell me, what does my tip say?"

"Well, this penny tells me you're a thrifty man."

Barely able to conceal his pride, the man utters, "Hmm, true enough."

"And this penny, it tells me you're a bachelor."

Surprised at her perception, he says, "Well, that's true, too."

"And the third penny tells me that your father was also a bachelor."