This is really timely for me as I just got out of the bathtub with my 3.5 YO DD and we had a similiar issue. I was reclining in the tub (which I do every great once in a while because she likes to pour water in my belly button
) and she asked where my poop comes out. I told her that that spot was called an anus and pointed to the general area and told her it was farther back. (I didn't "spread" or anything as some of you have put it.) Then she asked (predictably) where pee pee comes out. I told her what that was called and that I did show her. Then she asked where my vagina was. I had a second to think about what to do and in the end I just pointed it out in the same general way - pointing to the area it was hiding under. She said, "I don't see it - where is it?" I said, "It's kind of buried. Why don't you look for yours?" She also said, "A vagina is your baby hole, right?"
Then she wanted me to show her where they all three were on her.
I feel fine about that encounter although she didn't get as much detail in what I showed her on me or what I showed her on her. I did what I felt comfortable with in the moment. I think it would have felt different to me if she had asked when I had clothes on - her curiousity was situational. I guess that's what I think we all should go on is what feels comfortable. As we teach our children to have boundaries about their bodies, we should keep boundaries that we feel comfortable with. Some of you have already said this much better than I. I wouldn't judge anyone for showing her children nor would I judge someone for not. We all have different comfort levels. Also I don't have boys so it's hard for me to imagine. I'm trying to imagine my daughter and my husband but I can't really because he's uncomfortable with her watching when he's peeing or something so I can't imagine him being willing to show her. Anyway. I really do feel that it's all about comfort level.