Long ago when my child (now three years old) asked "what's that" we decided to not use any euphemisms so we told him that was his penis. He didn't say anything else about it for a while, but lately he talks about his penis a lot.
When I was changing his diaper he starts "Daddy, is that my Penis?" Yes. "Daddy, do I have poop on my Penis? Yes. "Daddy, are you going to wipe my penis?" Yes. "Daddy, do you have a penis?" Yes. "Daddy you're a Penis". I was a little stunned. What exactly should you say when your son calls you a penis. I knew my first response was not appropriate because laughing hysterically would probably not prevent him from calling anyone a penis in the future. So I held the laughter in for a while and told him it was not nice to call people penises. Once I got him off the changing table I went in the other room, shut the door, and laughed it out.
He also likes to point out to his mother that he has a penis and baby has a penis and daddy has a penis, but she does not.
Part two, why I don't change my son's diapers in public anymore.
My son does not like to have his diaper changed, and is sometimes quite uncooperative about it. I was in a family restroom at the mall changing his diaper and when I started to wipe him he got all upset and started saying things like: "Don't wipe my Penis, I don't won't you to touch my Penis, You're hurting me." Then he was squirming so much I thought he was going to fall off of the table so I put on hand on his stomach and he starts saying "Let me go, Let me go, get your hand off of me, don't wipe my penis". By this time I am looking around to see if anyone is in the changing area. I then realized that looking all around might make me look guilty of something. Fourtunately no one happened along to question me. From here on I have done all I can to avoid changing him in public.