Personally, I consider his behavior as child molestation. If one of my grand daughters was in his class, he’d rightly be prudent if he took assessment of the impact of what he’s doing.
It IS. And so is all "sex education" in gov't schools. If you doubt me imagine what would happen if you took a child aside and gave him that information in private. Corruption of a minor, any one? But do it to a whole crowd of kids in a darker room owned by the gov't and you may corrupt away!