What on earth about sex and relationship education might be inappropriate to teach at a primary school? Hmm, let me think about that one, you know I can't come up with a single thing! Let's get all the pictures and the horror stories out!
Don't read Brave New World...
For a very long period before the time of Our Ford, and even for some generations afterwards, erotic play between children had been regarded as abnormal (there was a roar of laughter); and not only abnormal, actually immoral (no!): and had therefore been rigorously suppressed.