When I Feared for My Sibling's Safety Because of a Game Night Mishap

So here’s the deal: my family gathers once a week for what we call “Game Night.” It’s supposed to be fun, but sometimes it ends up being anything but. Last weekend, after hours and hours of playing board games that seem to stretch on forever (because apparently nobody can agree on when to stop), we decided to play a card game called “Cards Against Humanity,” which my younger siblings had never heard of before. I tried to warn them about the mature content beforehand, but they insisted it would be fine since everyone was just in it for laughs and there were some older cousins around too who would help keep things toned down if needed. Fast forward a few rounds: my youngest brother starts asking questions that have nothing to do with the game’s intent. He asks out loud how people deal with being bullied, what they think about animal rights activists who might break into labs, and other topics that feel more like therapy sessions than card games. I start getting uncomfortable because it feels like he's trying too hard to fit in by pushing boundaries we agreed not to push. Then the older cousins decide to playfully challenge him on some of his more sensitive questions, suggesting answers that involve teasing or making jokes about personal issues. He starts laughing along with them but I can see how uncomfortable and even hurt he is under all those fake laughs. The game turns from silly fun into something darker. By the end of Game Night, I’m so worried my little brother might be feeling isolated and misunderstood that I spend an hour after everyone leaves chatting with him, making sure he’s okay. This has me questioning if it was really necessary to play such a divisive game in our household in the first place. Was I being too overprotective? Should I have just let them go ahead and play as planned without stepping in? Or did I actually do the right thing by trying to look out for my sibling's well-being during what could have been a really tricky situation? Thoughts?