The Cousins (1959) on Netflix

A pair of cousins share a flat, but animosity begins to build between the two when a woman gets involved.

Charles is a young provincial coming up to Paris to study law. He shares his cousin Paul's flat. Paul is a kind of decadent boy, a disillusioned pleasure-seeker, always dragging along with other idles, while Charles is a plodding, naive and honest man. He fell in love with Florence, one of Paul's acquaintances. But how will Paul react to that attempt to build a real love relationship ? One of the major New Wave films.

—Yepok

Charles, a young provincial student, arrives in Paris to take a room at his cousin Paul's. Paul, also a student, seems only to be interested in hanging out and partying. Charles falls in love with Florence, whom he meets at Paul's favorite hang-out. Clovis, a trickster friend of Paul's, who is always turning up at the flat, has a hand in manipulating the action. An early and highly regarded work by Chabrol.

—Chridman