I believe in having sex education in schools because of the importance of it. Even if you don't want your kid to know about it, They should still learn about safe sex and STD's. Sex education in my school even taught us about healthy relationships and how to see unhealthy ones as well as getting out of one or helping a friend with one. To me unwanted pregnancy, STD's, And healthy vs unhealthy relationships makes it worthy to have this education in schools. Worst comes to worst and you don't want your student learning it, They send home a paper for you to sign if you don't want your child to participate in it.
It needs to be taught by parents. People will say that parents just aren't teaching ti so it is better for their kids to learn it, But what of those that are? Parents should have control over their children's education and this is an area where that is especially true.