I think it is part clueless, part lack of education.
Ok I am not easy to mistake as female. No breasts doesn't help.
But then you counter with, what, do all the men in this town carry purses wear women's jewellery and women's hair styles?
How dumb can people actually be?
I suppose so many people simply can't comprehend that to some of us, you can be neither straight or homosexual.
Been thinking on that, and yeah I am neither straight or homosexual as the words are normally used by them.