Being a socially transitioned transfem that has not begun her HRT yet, I have received some flirty attention from gay men, and there's one point that makes me a little uneasy about it:

It makes me feel like they see me as "male enough". I do not want to be an attractive man. Much, much better to be an unattractive and unwanted woman than an attractive man. It's not possible creating a connection to a person if I strongly suspect they are invalidating me in their head.

If you see them as women – or at least as a category that is very clearly not connected with the category "men" –, then absolutely no problem. I could imagine spending an evening with a gay man, although I don't really understand how he's literally gay if he truly likes me as I am. But yeah, at the same time, if he's unable to find cis women attractive, he isn't really straight either.

So, at least I'd need something that makes it clear I'm not being seen as a crossdressing man, because that's not what I am. It would feel insulting to me to be seen as something else than what I am. (And of course, if someone tells me "I do not see you as a crossdressing man", then that kind of makes me feel invalid as well, because it implies you had just been thinking I might be just that.)

Someone who's been long enough on HRT might be much less sensitive about this, I'd guess?