Things that make Gavin go "Hhhmmmm"

This morning we were getting ready to go to the gym and were in the bathroom. As many of you already know, Gavin is fascinated with his "male member". He is just into that phase where he identifies who are boys and who are girls...and he knows that boys have a penis and girls do not. So today he watched me go to the potty and said..."Hmmm. Mom? If you don't have a penis, how do you go peepee?" I didn't really know how to answer without laughing.