> Teaching happens the entire time kids are at school even when just talking to their teachers so a teacher mentioning their family, their kids, their spouse, changing their last name because they got married, changing from Miss to Mrs, wearing a wedding ring are all expressions of human sexuality.

But that's exactly the problem. Parents want to insulate their young children from discussions of "human sexuality." We have strong social conventions to be able to talk about things kids are exposed to--weddings, etc.--without expressly talking about sexuality. Many parents, however, no longer trust teachers to adhere to these social conventions.