is he bi? Or is he one of those "I am not gay but I love you because you are you" squad?

INDEED

Or he could just be a person that falls for whatever they like why does it matter what his sexual identity is

I was thinking the same thing too. And I am just asking because it piqued my interest, as long as he doesn't do anything that would hurt the uke or play with his feelings I am fine by that.