A man and his son were walking through a field, and saw two dogs mating. The little boy asked his Dad what was happening.

The Father replied, "Well, son, they're making a puppy."

The following evening, the little boy was thirsty, so he went from his bed to get a glass of water. Not being able to reach the glasses, he walked unannounced into his parents bedroom, who were making love in their usual missionary position. Confused, the boy asked what were they doing.

The Dad responded very slowly and caringly to his impressionable little boy, "Well, son, we are making you a little brother."

The little boy replied, "Please turn Mom over, Dad, I'd rather have a puppy!"