The Dreamers

Matthew (Michael Pitt) gets drawn into the semi-incestuous relationship between Theo and Isabelle Louis Garrel, Eva Green). Despite his occasional attempts at breaking the siblings' unhealthy dependence on each other, he finds himself powerless to change their relationship. Not willing to give up his intimacy with them, he prefers to join in a self-enclosed love-triangle, the three of them effectively closing themselves to the outside world. When Theo and Isabelle's parents return from vacation and discover the appartment in a state of chaos and the three asleep naked together in the living room, they decide not to deal with it directly, instead leaving money and sneaking away. Isabelle wakes up and discovers the check, realizes that her parents now know everything, and tries to fill the appartment with cooking gas so that they would all die together rather than face the consequences. However, before they can asphyxiate, the street riots of 1968 start in earnest and someone throws a stone through their window. They all wake up and run out to join the rioters. Theo takes a molotov cocktail to throw at the police. Matthew tries to get him to choose pacifism over violence, but Theo rejects him, and Isabelle goes with Theo. Matthrew then realizes that his rational idealism never had a chance against Theo and Isabelle's emotional, self-destructive hedonism, and he turns around in sadness, while Theo and Isabelle vanish into the chaos behind him.
Thanks, Eytan Z!