Le Grand Amour - Pierre Etaix (1969)

Twenty-five year old Pierre is a man who likes to play the field, about which most of girlfriends are aware. Pierre falls into a relationship with Florence Girard, who he loves and marries more out of circumstance than anything. Their life is less than the exciting one he envisioned for himself, as he ends up working for Florence's father in the office of the family business, a tannery. Old habits surface as he embarks on a few extramarital dalliances, which he sees solely as distractions from the problems of marriage, one of those problems with Florence being her mother, who Florence resembles. Thus he sees his future as that of his staid in-laws. It isn't until he is in his late thirties that he truly does begin to contemplate ending the marriage, all because of his new eighteen year old secretary, Agnes, with who he believes he has fallen in love. The questions become whether he will do anything about it, if his feeling for Agnes truly is love, whether Agnes has similar feelings for him, and how Florence truly feels about marriage to him after ten years and visa versa.