I taught OWL classes to 1-2nd graders. They parents are in the room for those classes. It’s completely age appropriate and we mostly talked about hygiene, what our body parts were called, and that our bodies belonged to us. We covered in appropriate touch and what to do if someone touched you or asked to touch you in your genitals. We discussed different types of families and relationships as well. The last session was how babies are made and we had two versions, the parents had a choice which version they wanted and in one of them we briefly mentioned that the man’s penis went into the woman’s vagina. Here’s the thing, I knew this by the time I was in first grade, so did most of my friends. I learned it from an older kid, and everything I learned about sex was mostly wrong and distorted. OWL made it less taboo to talk about with your parents. Every parent, even the ones who were hesitant to sign up, ended up being very glad they did.