The so-called sex instruction which is given by parents and schools usually consists of a certain amount of information concerning the anatomy and mechanics of reproduction. (Alfred Kinsey)
I assume that you are suggesting that encouraging heterosexuals to accept homosexual behaviour as normal and acceptable should be part of a comprehensive sex education. I agree. Ideally everyone should demonstrate tolerance for other people's sexual preferences. Equally, everyone should show consideration for the preferences of others. Sexual intimidation is a form of bullying that is unacceptable in any civilised society.
Sex education, if it is to be comprehensive, should cover all aspects of sexuality including orientation, sexual response and sexual pleasure. These topics are omitted from what we tell children because it is assumed that everyone has access to erotic literature and pornography. But since these sources are fictional, they do not constitute an authoritative source of information about human sexuality. Women's objection to any sexual content, even when it is educational in nature, is an obstacle in providing sex education that refers to any of the erotic stimuli that cause orgasm.