Someone who fetishizes trans people. You find trans people hot? That's totally fine, you can have preferences. But grouping post op trans women and pre op trans men sexually is saying that they're being viewed as women regardless of their identity.
If you wanna fuck a trans person, it should be because you're attracted to them. Maybe you like boobs and penis together and that's fine. Maybe you like a masculine chest and a vagina. You can be attracted to a certain intersection, even if that intersection is a straight one. But fucking them because they're trans and exotic is chasing. If you like women, fuck trans women. If you like men, fuck trans men. But don't just randomly flip them around like there's no difference to you.