I personally keep my secrets mostly to myself. When I write fiction on AO3 I have a decent following and they know me as a straight male. I was born a male and legally am a male. I identify yo my closest friends as transgender. If I had been born after 2000 I would have had sex reassignment done. Still I see myself more as a woman and would be considered bisexual. I hesitate to admit that even here and would never on my non erotic accounts where I write stories that have no snuff erotica or other elements that make up my stories here.
I for the most part identify myself as male, which is the sex I was given at birth, yet I cannot deny that in erotic matters I tend to identify mainly with women, generally as victims of something or as people humiliated by some others' deeds or, why not, by their own choice.
In short, I do not claim to call myself 'transgender' or something, however I generally fantasize from a woman's point of view (or at least, from what FOR ME is a woman's point of view) in all sexually stimulating matters.
If I were a beautiful woman, I like to imagine that I would be a BDSM porn actress, so that everyone can recognize me when I walk down the street, remembering my orgasms, my tears, my pain.
In an even more imaginative scenario, I like to picture myself as a woman marching toward her own painful, humiliating execution: afraid but curious to undergo on my 'female' naked body a unique and, alas, deadly experience, unknown to most.