It's not gay if your balls don't touch.
It's not gay if he cums first mate.
Jokes aside, it's not gay or bisexual at all. If you're attracted to someone who looks like a woman then it's gynephilia (attraction to feminity i.e the feminine form).
We can debate for days if you consider a transgendered woman an actual woman but in the end, the attraction is towards them looking like a female and being something "exotic." Most men won't then go and get fucked up the ass by an actual man or look up gay porn of two muscular hunks getting it on, well except the guys over on HA (aka the escort forum for tranny chasers) who enjoy "sucking on the pussy of a crossdresser in a wig" heh but those guys are nuts.
It's not gay to enjoy anal simulation either as many men can and do enjoy pegging with a strapon with a genetic woman.
Personally I'm not interested being done up the ass, I visited a few trans escorts in the past when I had a fetish but kept it vanilla. I'm done with it now, the fetish seems to have gone, thank God, I didn't fancy being a tranny chaser. In the year I was interested, I was thinking of shemales often. I blame it on porn, I watched one shemale video once and started fantasising over it.
Not saying I wouldn't have sex with a trans again but I don't think I would go actively seeking and paying for it again unless the itch comes back but they never seem to. Once I was only interested in Asian girls, then Latinas and now my thing seems to be for MILFS.
If you want it though, go for it. Who's going to know, that they'll label you? Alternatively just go see a dominant woman with a strapon on to suck on if you've always wondered what it's like to give a blowjob or take it up the ass. Lol
My only warning is to not let it make you into a tranny chaser who only gets off only on transgendered women.
Trans escorts charge way too much anyways for an experience you can get from a genetic girl which may have been one of the things that may have contributed to putting me off as I could fuck blonde Russian chicks close to my own young age for £80-100 as opposed to a late twenties ladyboy from Thailand, as for the Latina shemales? £200 for an hour with someone who still has some masculine features? No thanks.
The other thing that put me off was all the offers of bareback and ones I discovered that previously did it.