Here's a question: Should a trans person tell the person with whom they're intent on developing a romantic and/or sexual relationship that they're trans? And, as a follow-up: When? As in at the very start of their feelings of attraction to the other person, perhaps over dinner on a blind date, or later on? Should it be expected that the trans person reveal their trans status at all?
Personally, I'm certain that if I got into a romantic and/or sexual relationship with a man (I'm a gay man) and then found out that he was originally not male*, that would be incredibly aggrieving. (It's not just me: some years ago, the first episode of a UK Sky TV dating series was in production in which participants, who were ordinary members of the public who had successfully applied to be on the show, were hooked up, and went on a series of dates with, a trans person. Only after the conclusion of the dates would it be revealed to the participant that the person they had been dating was trans. Obviously, the principle 'entertainment' factor of the show was in viewers witnessing the reaction of the participant to that news. The production was scrapped after the first participant, the secret having been revealed, punched the producer in the face and stormed off.) (Also, there's the question of the use of the term 'homosexuality', suggesting that something like 'same-(perceived)-gender attraction' be more appropriate.) But why should it matter? Logically, if, to me, the trans man is convincingly a man, up to and including his intimate anatomy and the satisfactory performance of same, and I'm attracted to him, what's the problem? I can't come up with a reason as to why it would be a problem; however, I still would not want to be in a relationship with a trans man, and would be aggrieved to find out if and that I was in such a romantic and/or sexual relationship.
So, here's a question: Is it transphobic for me to discriminate against trans men when it comes to with whom I embark on romantic and/or sexual relationships?
My answer is: No.
There's something special about the sphere that is romantic and sexual relationships that sets it apart from other spheres of relationships, such as familial, platonic or collegial ones.
There occurred, on then-Twitter; now X, a recent debate over whether or not having in one's online-dating app preferences the fact that people of a specified skin colour need not reply was racist. Well, it could be. If someone was pre-emptively rejecting approaches from people of that skin colour because of a preference against merely and literally the skin colour (indeed, perhaps claiming that they held a preference against white-skinned people who had a sun tan), thus not at all upon that skin colour being preceived to represent some or other ethnicity, then No (however, it could be the case that that preference was mapped to, thus reflective of, a subconscious bias against some of other ethnicity perceived represented by that skin colour, thus racist). But, in most, I think, instances of people stating 'preferences', these are not of the nature of rationally-thought-out, chosen positions; they're of the opposite nature, which is to say they advise of to whom one is emotionally 'attracted to'. But what difference does it make, anyway (remember: we're talking only in the specific and especial context that is romance and sex ('sex' as in 'sexual activity'))?
People are attracted, or unattracted, to others in all sorts of ways. It could be according to presentations of aspects of the other person's physical appearance, such as: eye colour; being tall(er) or short(er); being slim; being large around the waist; having long legs; large breasts; etc, then there are psychological presentational aspects, such as: personality; intelligence; sense of humour; etc.
When the context is not of romance and sex ('sex' as in 'sexual activity'), it's wrong to discriminate for or against others on the basis of the above—and plenty of other—presentations. But, when the context is that of romance and sex ('sex' as in 'sexual activity'), it's different. Otherwise, taken to it's logical conclusion, it is wrong to not be romantically and/or sexually attracted to everyone. Imagine someone on a date being told by said date that they must find them sexually attractive and, therefore, have sex with them otherwise they're being '-ist', racist/lookist/'weightist'/whatever, in some way. It's as daft as claiming that male homosexuality, as in homosexual males, in their not being romantically and/or sexually attracted to, even in being repelled in that context by, females, is therefore misogynist. Ridiculous.
*by medically-qualified assignation, ideally by genetic analysis, otherwise by some or other analysis at birth