"LGBT behavior" is one of those little semantic tricks some people think they can use to outsmart reality. Like calling it "The Democrat Party".
It just confirms you are a moron who believes in magic: If you can just say the right series of words then all the gays will decide to be straight.
They can't face the fact that most people exhibiting "LGBT behavior" do it because they are LGBT. Of course bisexual people confuse the issue because they really can choose a straight relationship or a gay relationship, but the number of bisexuals is much smaller than the number of us who really have no choice. And "people who have no choice" includes heterosexuals as well!