Where's baby's belly button?

D has always had a weird obsession with belly buttons, mine in particular. Now he has learned that he has a belly button too and so does Daddy. Most of the time he can't get to his belly button because it's neatly tucked away behind his onesies. Once he gets his less modest pajamas on, however, and we ask him "where's your belly button?", he first points to everybody else's belly buttons then searches through his fat rolls (he does have a couple!) to find his own. Paul also chases him around while saying "belly button" (in a ticklish voice, of course) and D runs around (walks very fast and shakily) holding his shirt up.