Credit Geody, my friend from out west, with this one...

An elderly man goes into a brothel and tells the madam he would like a young girl for the night. Surprised, she looks at the ancient man and asks how old he is.

"I'm 90 years old," he says.

"90!" replies the woman. "Don't you realize you've had it?"

"Oh, sorry," says the old man, "how much do I owe you?"