Fake it till it's real

Muse A Is gay. Muse B is straight and has a fiance. Both are in a pretty big idol group and do skinship with eachother. Muse A falls for Muse B but says nothing, but when Muse B (the straight one) falls for Muse A, it's a different story. What happens when the straight male falls for his gay bandmate, do they keep it quiet and behind closed doors, do they ignore it, what happens to their relationship and their band membership.