WARNING: This may not be suitable for everyone. And by suitable I mean a kid shouldn't read it nor should parents/adults/teens who giggle when they see the word for certain "private" body parts.
We've tried the approach in our house to say things like it is. That means we don't have nick names for body parts and if my kids ask a question we give the a detailed (age appropriate) answer.
Remember...I warned you. Seriously stop reading if you can't handle it.
So its not uncommon for Elijah to run out and say "Mommy my penis is growing" when he wakes up in the morning with man parts standing straight up. Its also why we've had awkward conversations like when Jordan asked when she would grow fur on her vagina. Or when Taylor asked if she could have mountain boobs like mommy someday.
We don't shy away from these conversations. We don't laugh and draw attention the conversation. We answer their questions and move on.
Some parents don't appreciate this so much and freak out a little when my kids reference these body parts with their real name. I get it. Its not an approach everyone agrees with, but its what we do and I don't have any intention on apologizing for it.
I will correct my kids if they are using these terms without purpose. Like just yelling penis at the dinner table, but if they happen to be in front of your kid and say something like "when I peed my vagina hurt" I will not correct them or scold them. In our house its no different then saying "wee wee" or "private parts" instead.
Aside from that my kids know other things typical kids their age don't know. Because if they ask. We answer. Its why my kids know Santa and the Easter Bunny aren't real and just pretend like in movies (and we do tell them not to talk to other kids about it because some mommy's and daddy's like to play pretend with their kids so other kids might think they are real).
It is also why Taylor can explain to you how some babies are born with genetic disorders (at a 6 year old level). It also means that Taylor knows why women have periods. It also means the Taylor knows how babies are formed (that an egg from a mommy comes together with an egg from a daddy and makes a baby)... thank the lord she hasn't asked how those eggs come together...well not yet anyway. And in case you haven't picked up on it, Taylor is the much more curious kid of ours. The other 2 haven't asked nearly as complex questions yet.
So today this conversation happened
T=Taylor (female, age 6) and J=JC (male, age 8)
T: do you have sister?
J: my mommy doesn't have one yet
T: well you just need to tell your daddy to give her an egg
Me: Taylor tell JC about your school ::topic successfully changed::
Yeah. So I won't apologize for that conversation happening, but I'm wise enough to change the topic so my 6 year doesn't start explain the birds and the bees to your kid. So I'm not that horrible of a person, right? :)