On the basis of so many responses, obviously there is still a tremendous misunderstanding--lack of education--about what biologically generates sexual orientation and how it is different from gender assignment at birth. Even that wouldn't necessarily dispel all fears and doubts.
One's masculinity or femininity is determined by many factors and, like so many qualities, runs along a scale and upon different "tracks" if you like. To be "honestly" attracted to someone means to be attracted to those qualities. Not to their sexual anatomy.
I believe the adequate phrase there, in response to those who don't quite understand, no matter what your sexual orientation may be, is "grow up."