Nearly a decade later, when the never-seen Paul drops dead, Marianne becomes available again, an opportunity that Abel hopes to seize. Marianne’s young son, Joseph (Joseph Engel), a mystery buff who uses an iPhone recorder to keep tabs on intimate goings-on in his home, suggests to Abel that Marianne has gotten away with murdering Paul — a theory that Abel investigates without ever quite resolving . Complicating matters, the funeral puts Abel back in touch with Eve (Lily-Rose Depp), Paul’s younger sister, who has nursed a crush on him for years and is prepared to announce as much to Marianne.

Although Abel is the movie’s fulcrum, Marianne and Eve also participate in voice-over duties — a destabilizing choice that seems perfectly in keeping with the characters’ one-upmanship and the movie’s off-kilter comic tone. Garrel finds visual ways to emphasize a lack of balance. (Indeed, given who is holding hands in the closing scene, asymmetry may be the film’s overriding theme.)

Conversations are often shot in uncomfortable close-ups, and the cinematographer Irina Lubtchansky’s unobtrusive shading hedges against the potential for talky drabness. In some respects, the film resembles Éric Rohmer’s moral tales, but amorality — all three principal characters are effectively dancing on a man’s grave — seems to be the order of the day. In this low-key, engaging comedy, a protagonist must become unfaithful to prove his fidelity — and turn selfish to prove that he cares about people beyond himself.

A Faithful Man

Not rated. In French, with English subtitles. Running time: 1 hour 15 minutes.