A boy and his father are walking in the park.
The boy sees a male dog mounting a female dog. He asks his dad, “Dad, what are they doing?”
Dad thinks for a second and says, “Well, son, they’re making a puppy.”
This satisfies the boy’s curiosity, and they finish their walk.
Later that night, the boy gets up for a drink of water. He passes his parents’ room, and they’ve carelessly left the door ajar. They’re face-to-face in the throes of passion.
The little boy asks, “Dad, what are you and Mommy doing?”
The startled dad hesitates for a second, looks up, and says, “Well, son, we’re making you a baby brother.”
And the kid says, “Well then, can you turn Mommy over? I’d rather have a puppy.”