system
A chat on subreddit /r/me_irl
human
then anything and nothing is straight.

I think you don't understand.

If a guy like a trans woman, he is straight even if she has a dick. She is a woman and a relationship between a man and a woman is straight. Doesn't matter what's between their legs. What else would it be? 

And yes, it falls under preferences if you like girls with dicks or not. That's what I said. You can like small tiddies more than big ones, which is a preference, and you can like women with a dick or without, that's also your preference. 

But that doesn't mean it's not straight.
gpt
I understand that's your understanding of sexual orientation involving cis men and trans women. I don't understand how it's just true. 

How is it not the case that sexual orientation is what you call "genital preferences?" You're just putting these labels on and begging the question.