The relationship that develops between a sexy young woman and a wordy elder professional in Anne Fontaine’s The Girl From Monaco is also an Allenesque mystery. Sure, there’s probably no straight man alive who wouldn’t give in to the aggressive advances of a long-limbed weather girl whose résumé includes a tawdry reality show and delivers her forecasts with costumes and air-kisses. But why she becomes so taken with a plain-looking and fun-averse lawyer is a question only a scripter can answer.

Co-written by Fontaine and Benoit Graffin, The Girl From Monaco initially promises the French wit and whimsy of Graffin’s recent projects, Priceless and Après Vous. Fabrice Luchini (Fontaine’s fiancé) plays Bertrand Beauvois, an esteemed Parisian defense attorney who travels to Monaco for a high-profile murder trial. He’s surprised to find that a bodyguard named Christophe (Roschdy Zem) has been hired to look after him, and even though Bertrand insists it’s unnecessary, he soon uses Christophe to keep him company and help him get rid of pesky women who keep throwing themselves at the commitment-phobe. But he’s not too quick to dismiss Audrey (Louise Bourgoin, a Blake Lively–esque beauty), the barely clothed meteorologist who takes an immediate liking to Bertrand and is soon flinging her panties at him.

Luchini’s stunned expressions when Audrey turns up the heat as well as his amusing eloquence (“There’s anxiety in that hairdo!” he says of a tarted-up club cougar) are small pleasures in this odd film. The trial and any danger Bertrand might be in because of it are secondary to his tryst with Audrey—as well as to the jealousy of Christophe, who, like seemingly all of Monaco, was once Audrey’s lover, too. It’s funny when Bertrand drags his charge to obnoxious parties neither one of them would ever normally attend just because she will be there. And it’s kind of sad, but in that French farcical way, when Audrey has the lawyer jumping through hoops—or, in one case, into a pool—when he’d probably prefer to be sipping a nice brandy in bed.

But then The Girl From Monaco takes a serious turn, and although it doesn’t exactly ruin the lightheartedness that came before it, the new direction does leave you questioning the point of the story. (And with this, it becomes nearly identical to another recent French film about a weather girl and her older boyfriend: Claude Chabrol’s A Girl Cut in Two.) The script’s only attempt at a message comes in Audrey’s obsession with Princesses Diana and Grace, the former of whose death “when she had everything” made Audrey decide to start “smiling, laughing, being a really beautiful girl.” It’s a lovely insight, and as droll as Luchini occasionally is, Bourgoin is by far the brightest light in this story. The film’s love triangle and subsequent tonal 180, though, is a head-scratcher that renders it neither a comedy nor drama. What it feels like instead is a trifle—and not one compelling enough to recommend.