I am sorry but how would you know if you pass the requirements for him being attracted? You say he has a wife so are you really really sure he is into you, has he ever said it to you or are you assuming? I am sorry, I mean no harm I am just afraid you may end getting disappointed because it is not what you thought it was.
If men are attracted to you pre-HRT, they may be bi, gay or pansexual but very unlikely straight as even if you are seen as an extremely feminine guy, that doesn't equal woman. And you don't present femme in any way, so yeah. Sorry, I mean no offense.
EDIT: Also, you don't want to be the "other woman". It is a horrible situation both for you and his wife as he will tear you apart if you end up having an affair. You know he has a wife, so if I were you I would back off. And if he is considering doing it with you, he could do it to you later. So, my advice is to let it go completely. It is not healthy and I question whether you are really in love or infatuated.