“It’s so outdated, this taste for passion in the 21st century,” Charlotte (Sandrine Kiberlain) says in “Diary of a Fleeting Affair,” perhaps to the dismay of her companion Simon (Vincent Macaigne), though she’s referring to the art on the walls of the museum they’re touring and not the status of their relationship – or as Simon clarifies at one point, “an understanding.” If Charlotte wanted to be in a torrid romance, she wouldn’t be on a date with Simon, who is married himself and not so much looking for an escape from the relationship he’s in than intrigued by Charlotte, a free spirit who kissed him at a party and they end up meeting at a bar a couple months later.
It’s a premise that you know Emmanuel Mouret, who has made a career out of looking at the peculiarities that create compatibility in such films as “The Art of Love” and “Shall We Kiss,” will make a meal of and his latest is a total delight as Simon and Charlotte refuse to believe they’re falling in love with each other when that would violate the terms of their agreement, but the fact they see eye-to-eye on the pact itself suggests a real deep bond there. As interested in talking to one another as in sex, which they’ll later include in an online listing when Simon is emboldened to seek out another partner (Georgia Scalliet) for a threesome — a rendezvous that induces far more anxiety than pleasure — the infidels start spending their spare afternoons together, as likely to be seen at a bookstore as in bed. Mouret has become particularly gifted at bringing the surroundings into any given situation, making Charlotte and Simon’s initial encounter a riveting roundelay as the two feel each other out while dodging other bar patrons to get their drinks and when they start to see one another beyond the early frenzy of their affair, the use of bookshelves to obscure the couple when they know just enough to think they don’t know each other at all is as dramatically affecting as Mouret’s instincts for physical comedy.
Macaigne, a hangdog scene-stealer in recent Olivier Assayas’ recent projects “Non-fiction” and “Irma Vep,” and Kiberlain, who perfectly balances sensibility with a happy-go-lucky spirit to make Charlotte’s internal logic entirely reasonable, are an irresistible pair and Mouret and co-writer Pierre Giraud understand that their attraction, driven by a desire for independence, inevitably dooms any chance of a future in spite of their growing attachment to one another. Still, the joy of watching Charlotte and Simon match wits while being unable to recognize what’s in front of them is quite satisfying, particularly as you can lose yourself as they do in time when Mouret elegantly charts its passage in specific days at random intervals, and “Diary of a Fleeting Affair” has the the same thrills of indulging in something that may go against better judgment as its characters experience, though it can only be a complete escape from reality for those off-screen rather than on.