I don't think they're homophobes. Remember the gay pervert who touched him in the gym showers in one of the prev chapters? I think it was him. He is just a nasty low bastard.
they're just projecting their own homosexual desires, basically like bullies, they're insecure about themselves so the take it out on other people to make them feel the same way if that makes sense
Homophobes: "Let's fuck him!"
I know this is Yaoi, but wtf kinda logic??