If being gay is strictly about sex, then you could marry and have a family with a woman, and no need for romantic intimacy with another man - just sex.
Reread what I said: It isn't JUST about sex. It's about love and the capacity to experience it with another man. I am incapable of falling in romantic love with a woman, because I have a distinct need for that emotional intimacy with a man. I like sex, sure, but eventually sex is no longer going to be in the cards for one reason or another.
And my partner's gender will be a man.
The same thing applies to bisexual / pansexual.
What qualifies as discrimination is what happened earlier in this thread. "Trans men aren't men." Or "I won't date a man who is bisexual." No one has to date anyone. But to pretend it isn't discrimination is to lie to ones self. And that's why I hate the "gold star gay" nonsense.
As far as what Alex said - Straight men playing gay roles is not queerbaiting / gaybating. It's a performance. That includes in porn.