One day Little Johnny and his mom take a taxicab to go to his uncle's house.
On the way, Little Johnny gets in a curious mood and starts asking
questions.
He first says, "Mom, if dad was a dog and you were a cat, what would I turn
out to be?"
His mom says, "Oh dear, don't ask silly questions."
About five minutes pass and Little Johnny says, " Mom, if dad was a bear and
you were a horse, then what would I turn out to be?"
The mom gets angry and yells, "Little Johnny, that's enough. Stop being
silly!"
His mom tells the taxi driver to stop by a bakery on the way and she gets
out and tells Little Johnny she'll be right back.
The taxi driver starts playing with Little Johnny's head and asks, "Hey Kid,
if your dad was a street bum and your mom was a prostitute, what do you
think you would turn out to be?"
Little Johnny says, "A taxi driver!"

:D