Look, he ain't wrong. You ain't wrong either because that kid is a disrespectful shit, and he knows it, but I'm gonna come at this from his perspective cause it's one I know better.
But for example, we live our whole lives having people tell us to stop pulling the 'race card' and getting offended. Or publicly talking about shit that happens to us. The moment we talk about difficult things we have to deal with in society, if the person isn't also a colored person, they immediately get defensive and check out of the conversation. They walk away. They say they don't want to hear about it because hearing about it forces them to confront the issues and they'd just rather not because it makes them uncomfortable. They can change the channel on the TV when they encounter what they don't like. And it's like, congratulations you just exercised a right that we don't have.
So when you tell this kid he's behaving wrong without acknowledging that maybe he has a real, valid reason for it, it's doing that same damned thing we experience when it comes to racism and prejudice.
So fucking try to understand he and his friends are kids that fought a war and it fucked them up. They can't be normal and it's stupid for us to get mad when they don't react the way we want them to. Yeah, Marco's fucked up and his coping mechanisms are stupid, misplaced humor. But that's what he's got until someone can help him develop healthier ones.