When I was at High School (UK) (age11-16) I don't think I had any sex education relating to homosexuality. And while I can see the advantage of equality being expressed in the classroom by equal representation in the curriculum, I would prefer it not to be taught because:
1. It is unfair to teach an entire class about sexual practice which will only affect a small fraction, possibly even one individual in the class. If a class is not learning something relevant it gets bored, and then the jokes begin to fly.
2. I still cringe when I think of my sex education classes, when push comes to shove sex education can be expressed as: 1. Always wear a condom, 2. Monogamy is generally preferable. 3.STIs are bad, this is what they look like [disgusting pictures], if you get them, see a doctor. Since these essential elements apply to any sexuality, I don't think homosexuality based moduli for the national curriculum are needed.
I would also point out that since the Local Government Act 2003 (the repealing of section 28) there has been no significant change to the national curriculum, and no planned change in regard to sex education.
In regards to homophobia, while my sixth form is very liberal - with homophobia being utterly socially unacceptable - it does still exist, my only advice is confidence, and failing that complain to powers that be, if that fails keep complaining up the ladder until you hit someone sympathetic.
Readers in the UK may also find this interesting.