To be clear, we’re talking about books that have graphic images of sex. They wouldn’t be appropriate even if they involved straight sex. Don’t use LGBT acceptance to promote sexualization of minors.
Not long ago, I was 13. At that age, I read books like Slaughterhouse Five, Cat's Cradle, and A Clockwork Orange. The very fact I now have to type that I knew that sex was a natural part of life perhaps speaks to the deterioration of our educational standards. Regardless, even I understood then that the sexual perversion of those works weren't their raison d'étre. I'm grateful I had an English teacher who guided me in that respect. Likewise, I earnestly hope others have similar instructors, who don't define a work by its depictions of acts of reality, however sordid they may be.
That said, I've been trying to find an example of a book in the "book ban" discussion that contains problematic graphic sex content. I've tried looking and so far everything has turned up pretty empty.
Nobody thinks the book causes that sexualization. The point is that it’s an implicit sanction from parental and teacher authority.