A group of liberal caricatures get together for a dinner party, as they often do as friends. After the meal they move to the usual games, but one of the couples (who of course just came back from Burning Man or something like that) suggest something a bit more adult - group sex.
A Good Dinner Party is not a perfect film because it is a bit broad and could have used a bit more hate or teeth in it, but it works well because its targets are known and well-drawn. By filling the room with caricatures and stereotypes, the film gets to present a very progressive group who are comfortable pushing boundaries. In contrast to this one person feels uncomfortable and is forced to defend her backward and closed-off views - in particular that she doesn't like the idea that her boyfriend would have multiple gay partners during the proposed orgy. This gives the film some teeth in the way it shows the moderate in the room being pushed beyond their comfort zone in the name of liberal progress, but yet even the slightest word out of place and the rest of the room are clutching their pearls.
As commentary and comedy it is broad but enjoyable. The cast work well with stereotypes, and have decent comic timing. I would have liked more savagery in its content but it is still a nicely cringe-inducing but gentle mockery of progressives.
