So What Do You Call It?

I love words, but sometimes I'm unsure what words to use.  Case in point, what to call sexy parts when you have a toddler.  I'm on the fence on the issue and still not entirely comfortable with how I've chosen to handle the situation because I haven't exactly answered his question.

Penis and vagina may be technically correct terms, but they're so clinical-sounding and I'm not one to generally use such accurate language in everyday conversation.  My favorite names for genitals aren't appropriate for a toddler to use so I settled on calling my son's penis a "wiener" early on.  Wiener is such a fun word, totally neutral and almost universally liked.

I know that some parents will think I'm doing him a disservice by not using the proper term, but I don't care that he calls it a wiener.  I mean, we also call the lower abdomen a tummy or a belly when the stomach is not exactly in that area (it's more like intestines & reproductive organs) so it's not like we always use the most accurate term for human anatomy.  I don't see why I should a stickler for penis (hehe) if I'm not with other body parts.  And I'll bet that even the most penisy and vaginey parents are guilty not always using the correct term for every body part.  Specifically, most of them use the word vagina incorrectly whether they realize it or not. 

I have trouble with what to call girly bits.  As I stated above, my normal words for that part of my anatomy would probably cause some women to curl their toes.  Vulva is the obvious choice since it does, in fact, refer to the exterior area of a woman's nether regions.  I've thought about "vadge" as it is half of the name for the immediate interior of my lady parts and vagina is widely, though erroneously, used as the blanket term for the general vicinity. 

Why does this come up?  Well, because he still does occasionally see me undressed and he's asked, "What's that?"  My answer has been a simple, "It's Mama's."  Sometimes I'll just say, "Pubic hair," as that's technically what he's pointing at and, so far, that seems to satisfy his question. 

What do you call male and female genitalia when talking with toddlers?  Why did you choose the words you chose?