[Iwa narrows his eyes at the unsolicited advice - no, he doesn’t like this guy at all. If it weren’t for him supposedly being friends with Ren, Iwaizumi would probably just walk away at this point, but he respects Ren, and for that alone he stays - that doesn’t mean he has to be nice though.]

If you’re trying to get me to play nice with that asshole, then you’re wasting your time, and I don’t recall asking your advice.

[And why does it sound like this guy is threatening him?]

You can quit assuming shit about me while you’re at it. I ain’t scared of him or anybody.