I'm not 'cis-gender' (ridiculous phrase), I'm a heterosexual male. Like it or not, the vast vast majority of people are heterosexual, and therefore 'normal' by any objective measure is a reasonable word to use.
Being gay or whatever is perfectly OK, and discrimination of people of a different sexuality to those who have a normal sexuality is abhorrent, so I have no issue at all with an awareness of different sexuality being taught in schools, however, it shouldn't be taught in primary schools - that's too young for any sex education. As somebody has already said, let children be children.