Little Johny orders a taxi

Little Johny orders a taxi

So when Little Johny gets in, the driver starts trying to be funny and then he makes fun of the kid:

Driver: If your mom was an idiot, what would you be?

Little Johny: Well I would be an idiot sir

Driver: And if your dad was a complete retard, what would you be?

Little Johny: Well I think I would be a retard sir

Driver: And if your mom was an idiot and your dad was a retard?

Little Johny: Well sir then I would be a taxi driver