I think it is because Jun can't understand how parents couldn't love their children. I mean even thought his parents aren't often around they make sure that he's well taken care of, also his ex-crush's father complained a lot, but was still there and worried when he was injured. So maybe he thought eating together would make them include Yohan again. Sure it's a silly idea, that would only work in an ideal world, but don't forget they still just high school kids (at that the well off, mostly worry free kind)
I think we all see that, but at the same time being high school kids, I am a high school kid who has loving parents. Yet we’re at the age to know about respect, abuse, and the reality of others. It’s a matter of naivety rather than a teenager’s ignorance. Which is why I say i’m sad, but the outcome is their own faults.

i’m sad for everyone I also hate everyone. Why would you make your friends sit through a family dinner when he already told you that they’re abusing him. At the same time I never agreed with Yohan. I don’t agree with his actions then nor do I agree with them now. Jesus Christ everyone here is just effed up