The prostitute started becoming annoyed and said, "Get lost old man! You're ruining business"!
"Sure would like to get some action tonight", said the old man
"You've got to be kidding! You're too old! You're all finished".
"What did you say"? asked the old man.
"You heard me - you're all finished".
"Oh," replied the old man, "how much do I owe you"?