A little boy got on a school bus and decided to sit in the seat

 A little boy got on a school bus and decided to sit in the seat behind the bus driver.

He began to talk to himself:

"If my mommy was a mommy cow, and my daddy was a daddy cow, I'd be a baby cow."

"If my mommy was a mommy dog, and my daddy was a daddy dog, I'd be a baby dog."

"If my mommy was a mommy bumble bee, and my daddy was a daddy bumble bee, I'd be a baby bumble bee."

"If my mommy was a mommy unicorn, and my daddy was a daddy unicorn, I'd be a baby unicorn."

And he just kept going on and on and on and on talking to himself. The bus driver in front of him, started to get annoyed.

The bus driver said "Hey kid, shut up and stop talking."

Just then the little girl sitting across the aisle form the little boy said:

"If my mommy was a prostitute, and my daddy was a hobo, I'd be a bus driver."