A boy and his father were walking through the park one day. They happen to pass a pair of dogs mating. The boy asks his father, "Dad, what are those dogs doing?" The dad replies, "They are making puppies, son."

"Oh," says the boy.

Later that night the boy wanders into his parents’ room and finds them having sex. The boy asked, "Dad, what are you and mom doing?"

Dad says, "We are making you a brother or sister."

The boy asks, "Could you turn her over? I would rather have a puppy."