What is homophobic is that he's willing (reluctantly) to let Haru stay, even though he's never met him. It's only Haru's sexuality that makes him kick him out. Discriminating against someone on the basis of their sexuality is homophobic. Feeling negatively towards someone purely because they're gay is LITERALLY homophobic. I'm going to keep reading and hope he redeems himself, but in this chapter he's prejudiced and homophobic.
Well I believe being homophobic would be when he would kicked him out and not let him in again saying its because he is gay. You dont know his circumstances (maybe he was raped in past) and from my point of view he was already cautious of him - that last information was the last straw and he just snapped. For me it has nothing to do with his sexuality, it was just another reason to be cautious and he already had many of them.
"I'm not prejudiced," says the homophobic jerkface. But kicks the guy out immediately because he finds out he's gay, assumes that he'll get jumped just because the guy's gay, and makes "Don't touch me" a rule, because the guy's gay. Yeah, not prejudiced at all. What a dick.