So female twin Sara only human hetro partner is Liam?

Yeah, the Hawke/Anders thing was weird, since in this case his past with Karl was relevant to the story. I'm straight and romanced Anders as a female character, and hated how that was handled. Bi-erasure aside, he keeps something really important from only the female player. Recently someone made a mod to fix it so he talks about Karl as his lover with femHawke and I have it downloaded for if I ever do another DA2 run.

As for Reyes, I feel like it's not as bad because I don't really see a way to bring up his sexuality in the time with him we're given without it being awkward? Though the argument could be made for him having an ex-boyfriend who shows up instead of who we got, since the character is pretty minor. That would've been kinda cool, actually, since typically the bi males in Bioware games show a preference for women - or at least their past relationships with them are talked about more. But then the opposite would be true where a male player would have no way of knowing he's bi. Maybe if we get more content with him in a future game his past could be elaborated on and they could find a way to let the female players know. Selfishly I hope they do this... because it would mean more content for Reyes, period! 

As for straight female players 'only' getting one human option... so what if we had? That was true in the trilogy too. As it is, I think we got three really nice options - varied enough to where I feel like almost everyone should find at least one to their liking. An argument could be made for the fact that the only sex scene we get is with the alien... ironically the one romance where I personally would've preferred a fade-to-black... but I'm happy with the quality of our choices overall. Even Reyes being a 'lighter' romance doesn't take way the satisfaction most people got from his romance, even if we do hope to see it expanded on in DLC/future games.