Children need to be taught that
society sees gays as normal and equal. If you want to teach your children otherwise, nobody can stop you, just as nobody can stop you from teaching your children to wear white hoods and lynch blacks.
Education is an organ of society as a whole, not just the family. The interests of society as a whole are threatened by book-banning. Your wanting to ban books about gays is no different from banning books containing four-letter words, or banning books containing "unapproved" political ideas.
People who think they have all the answers usually don't understand the questions.