Having a boyfriend wanting to watch porn at all, but especially trans porn, would be a big turn off for me. A boyfriend that was at the stage of his life where he was interested in porn, would not be the guy that i would want to move on with. That's just me.
What SM said was right, it is your right to not want a guy that watches porn, or wants a man that no longer bothers with it. While there are many men that do, I believe there are just as many that wouldn't. So the choice of the type of behavior in a partner, is something that you can , not control, but choose.
Welcome! Well, here is my take on it. Ya, kind of gross. But people do fantasize about a lot of things they are curious about or that are 'forbidden' and it doesn't mean they'd act on it EVER.
I think a lot of people and men especially watch porn and it is fairly harmless. However, some take it to the next level and watch all the time and it interferes with relationships, etc.
But it's okay for you to be against porn. I personally don't like it for the denigration of those who are in it, the way it objectifies women (typically), the way it gives a false impression of what sex should be like and the industry as a whole being raunchy. My husband doesn't like it because he says it is all fake. You can have a discussion with your boyfriend -- and share your opinion and thoughts about it. If watching porn is a deal breaker for you, then you have to stick to that understanding that he may not want to give it up. Or says he will but with how easy it is to access it these days, he still may look at it.
a big question is how is your sex life? How is your relationship?
Anyway, so I wasn't sure what you were totally asking. It doesn't necessarily make a man gay or bisexual to watch porn with that subject matter. Could be but definitely could just be curious about a 'taboo' thing. good luck