I'm an Aussie so I can't comment on what your schools do, but I had 4 clumps of sex ed through school: 1 week each in Year 4, Year 6, Year 8 and Year 9. All treated very clinically and very biased towards procreative sex, as though our bodies are nothing but machines with elementary functions to perform. All done through a transimission approach, with no real chance for us to clarify any misconceptions we had or things we wanted to know. What, were they expecting I'd go home and ask my parents about any of the finer details I didn't understand? "Dad, I still didn't quite get the whole pinching the end of the condom thing, can you explain that to me?" "Sure son, get your dick out and let's practise".
Kids will also eat whatever they want, but I think it does help several of them to learn about nutrition. Otherwise, why teach them anything at all?
I don't understand why these issues shouldn't be taught the same way teachers are supposed to teach any co9ntroversial issue: cover the controversial sides, get students to research and then justify their own positions on the matter. For example, I recently did some work with my Year 4s about whether Australia was colonised/invaded and who arrived when. There are very differing views on this in the community. There were still very differing views at the end of the course, but my kids could justify why they took the position they did. Some of the clarified misconceptions, others changed their minds, others changed their minds after they heard other children's researched opinions. And none of them felt pressured to take on my loony leftist position (which btw I did not impart). Why not do the same with sex ed? Kids are going to come up with their own opinions around this age anyway, let's at least get them informed!!!!