Old man and a hooker

An old man is walking in Amsterdam and passes a hooker standing at her door.

She asks him: "Granddad, why don't we give it a try?"

He replies: "No girl, that's no longer possible for me."

Says the hooker: "Come on, what have we got to lose, we can give it a try!"

They both go inside. They undress and he performs like a young buck, giving it to her 5 times in a row.

"Oh my goodness", says the hooker, breathless, "and you said that it was no longer possible for you?!"

Says the old guy:

Spoiler:

"Oh, screwing is still going well, it's the paying that is no longer possible!"

Moral of the story: Mess with seniors and you’ll get screwed.