That's not what queer theory is though, it has nothing to do with sex.... Everything to do with gender and sexuality. If gender isn't a social construct, then none of it makes any sense. Try to think critically about this.
Men used to wear powdered wigs and make-up, these things used to be perceived as masculine. Now these things are considered feminine. If something changes with society, it is a social construct.... That's a basic way to recognize one.
Gender and sex are not the same thing, gender is your representation of yourself and sex is your reproductive organs. If they were the same thing, then all males would have viewed the role of a male exactly the same, but it is society that has homogenized such things.
Queer theory simply asserts that one sexuality is not better than another solely because of reproduction, and that these gender categories we use to describe what people act and how they behave are made up. If there is no socialization, there is no sexuality. If it were just me and some guy, if he was attracted to me he would smash me -- it really is that simple. Once you get society into it, everyone wants to categorize him based on what he is sexually attracted to -- define his sexuality. It IS a social construct because it's a made up way we categorize people. Just as gender is made up, because there are no classes of people that prefer one type of clothing or to wear makeup without a society.
All of this seems pretty basic, and also seems pretty easy to understand. Science has the explanations, you just have to actually read about it if you want to learn more instead of being critical of ideas before you understand them. The baseline tenets of queer theory are pretty hard to disagree with.