Yep, it's a case of everyone involved being bi, and in the same vein nobody really has a problem with the sexual orientation of the other characters.
They're the parts that are most blatently changed from the probable reality back then. And while I'm sure there are some fantastic stories that could have been told around that, it's just one of the things I picked to make it a bit easier on myself.
Since it's an adult game, and one where I do want to allow for the freedom to have people pick their paths how they want, it just felt like it would make it more difficult to shape the story around that.

So it's essentially a free for all. Everyone's bi, everyone's fine with everyone being bi, just go have fun with the characters you enjoy!