Toddlers learn by watching and copying Mommy and Daddy in the bathroom. When your son notices that Daddy uses the potty differently than Mommy this will open up a great opportunity for you to explain the basic mechanics of how boys use the bathroom. It is important when talking to your son about male body parts that you use the precise name. Teaching him to call his penis a "pee-pee" when every other body part has a more adult-sounding name may imply that his genitals are embarrassing.