My daughter gave this some thought, then asked, "Why do men have nipples? They don't use them, do they?" I answered that men don't use their nipples and that I don't know why they have them. I quickly added that she should ask her dad that question. She agreed thinking that he would surely know the answer.
Unfortunately, my daughter never did ask him. I think she forgot. Sigh.
That would have been friggin' hilarious!