This, but you do need to blame them all. You do need to confront them and put them on the spot. Make them feel bad for being dicks.
Well, I guess you can do that so long as its not directed at anyone specific. That is what will doom you. Direct it at the whole group. Still, itll be less drama and hard feelings and shitty atmosphere if you don't blast them all. I mean, im all for telling people to fuck off, but you gotta live with these assholes. Try the nice route first and if that doesnt work just get your revenge by eating their food.