I don't really think sex ed should be applied to younger children
If they say it'd 'make them have safe sex when they're older', ya right, it depends on the individual. Some may have safe sex and some may not
'bout 13yo or so would be right.
I always asked mum (had no dad when I was in primary school) how babies are made. She never explained HOW, she just said 'it comes from the mummy's tummy' geeez, I was like 10 or older then. Read 'Where babies come from' but no sex diagram. In year 6, we had sex ed. That was when I learnt more about the gender 'bits' (and we were told not to show the diagram of the uterus to the boys. Stupid, if ya ask me. Of course, I 'accidentially' showed the diagram to a guy behind me, he was like OMFG.)
Eventually we had a look on 'Adam's Human Body' (a bloody good CD-ROM), that was when I first saw how babies are made. I didn't get it at first then at a closer look, that was when I realised how it happens. I was like
But in year 7, it wasn't a huge deal anymore. Ain't emotionally scarred here either. But I wish my kid bro wouldn't wave his noodle around (thank god he doesn't do it in public)
(Always avoided nappy change times lol).