I don't see it as bi-phobic or any type of queer-phobic. In my head, my rationalization for thinking lesbian would be ok is that it would be easy for me to accept that we could never be a couple and then I could just have a strictly platonic relationship no problem. Is this so different from the "straight woman has gay man best friend" trope?

But if she were bi or straight then there would be an inkling in the back of my mind that one day maybe she could like me too. One, that would just be an uncomfortable way for me to live; and two, if she ever found out I think she would be 100x more creeped out than finding out before we roomed together.

I guess it's like the "men and women can't be friends" speech from When Harry Met Sally (which I don't agree with for friends, but maybe it's true for roommates). Is this bigoted thinking?