A French film that defies the cliches - almost : Mademoiselle Chambon

A lot of spoilers here, so don't read this if you plan to see "Mademoiselle Chambon," which is a very atypical French movie - or at least it seemed to be - up to a point. Simple story involves a man, Jean, who is in builder/carpenter, working class guy in a small French town, gets to know his young son's schoolteacher (Mlle Chambon, though her name is barely used in the film). The teacher is obviously very lonely, and very attracted to Jean - (inappropriately) hires him to repair windows in her apartment/house, and thus begins a flirtation - he asks her about music (she plays violin), he stops by to borrow CDs, eventually he takes her hand, they kiss, but then he backs off. Well, good! He's in a very good marriage it seems, a totally good guy, kind to his elderly dad, a devoted father himself - at last a French film that defines the cliches, a film in which the characters, or at least one character, will take a moral stance and note treat marriage and family as some inconvenience hindering pursuit of the pleasure principle. Mlle ,Chambon herself is predatory, but not in Glenn Close-evil way - just vulnerable, lonely - and troubled and all too available. You keep wanting her to go out and meet some people her own age (Jean is badly miscast - at least 20 years too old for the part). But then, finally, minutes from the end, Jean gives in to his what seemed to be harmless and idle fantasies and they have sex and he says he will follow her as she leaves for her (family) home in Paris. Obviously, the relation would last about 2 weeks: loneliness on her part and on his part a fascination with a level of culture and education far different from his own life. Ultimately, his wife realizes the attraction between the two; Jean takes off for the train station, but, cf Casablanca, he can't board the train - becomes more a Brief Encounter than a reckless French romance. One interesting observation: the French working class are obviously far more prosperous than ours, in that Jean's life and circumstances look very comfortable, similar to the teacher's if not better. The movie is about class, but not so much economic class as cultural and familial (the teacher from a prominent Parisian family, we gather). All told, a pretty good if slow and quiet story that loses its bearings toward the end.