Fortune teller

A man was wandering around a fairground and he happened to see a fortune-teller's tent.

Thinking it would be good for a laugh, he went inside and sat down.

"Ah..." said the woman as she gazed into her crystal ball "I see you are the father of two children".

"That's what you think" said the man scornfully.

"I'm the father of THREE children".

The woman grinned and said

Spoiler:

"That's what YOU think!"