think we need to teach them sex education when they are in primary. But of course, the attitude of schools and teachers are important as well. Sometime I still think HK's schools and teachers still avoid discuss SEX with students in depth, I think their attitudes should be more positive. Now they can learn things through many ways. 與其 let them "fancy" about Sex or what is feel or like , why not just tell them what's SEX. If we can stop them having sex, then we should teach them what is "safe sex".
HAHA, maybe it's too early for our kids, but think we all need to have this kind of preparation.