Cirrus is that one guy who is definitely not straight but everyone ignores it

Right. Maybe because he is handsome, pretty and hot, it isn't show a lot in the story but men and women seems to like him, so they don't mind.
I think he might be Bi and not gay as Skylar. Anyway i hope his classmates accept him once he comes out.

Ye like they all shrug their shoulders and are like “it was quite obvious”