Thank goodness for Leslie Mann.

If not for the nutball charm of this tight-wound whirlwind, the dispiriting Hollywood sex comedy The Other Woman would be close to unbearable.

A high-concept bedroom (and living room and kitchen and foyer) farce about the improbable alliance among a cheated-on wife (Mann), her husband's girlfriend (Cameron Diaz), and her husband's other girlfriend (Sports Illustrated cover girl Kate Upton), The Other Woman is a revenge comedy in which the instruments of comeuppance include laxatives, hair-removal products, and hormone treatments.

Once you've discovered that your spouse (the male model-handsome Nikolaj Coster-Waldau) is a serial philanderer, the only recourse is to dispatch him to a toilet stall with a major "fecal incident," right?

And if that's not enough in the way of sophisticated humor, how about the sight of a spotted great Dane relieving himself on the otherwise-pristine floor of a high-rise apartment belonging to your husband's mistress? Not that she - Carly, a Big Apple lawyer, played by Diaz - even knows she's a mistress. She's not a homewrecker, just a woman with a healthy sexual appetite. When she discovers Mark (Coster-Waldau) is married, she's ready to call the whole thing off.

But Mann's Kate, a heretofore trusting suburban wife, is still processing her husband's infidelity. She needs to talk it through with Carly - in Carly's office, at a bar, and then back at Carly's place, where the women get soused, slather makeup on each other, and hoist skimpy lingerie aloft in a spirit of twisted sisterhood.

Mann's at her best confronting and then commiserating with Diaz - ditzy, arms flailing, stammering, and squeaking, Lucille Ball and Olive Oyl rolled into one, in panic-attack mode. We've seen glimmers of Mann's daffy genius before. She's writer/director Judd Apatow's real-life wife, and he made her his leading lady in This is 40 and Funny People.

Diaz is Mann's straight (wo)man, offering hard-won counsel of the sexual and relationship kind. By the time Upton's curvy Amber bounces along (on the beach, in a bikini, of course), Carly and Kate have bonded, like totally.

The Other Woman was written by a woman, Melissa Black, and directed by a man, Nick Cassavetes, who has shown some affinity for "women's stories" (the Nicolas Sparks adaptation The Notebook, and My Sister's Keeper, also with Diaz).

It is what it is: a studio take on the sort of thing the French have been known to pull off. Extramarital hijinks, adult, and absurd. In the case of The Other Woman, though, the laughs are mostly adolescent-rank.

The Other Woman ** (Out of four stars)

Directed by Nick Cassavetes. With Cameron Diaz, Leslie Mann, Kate Upton, Nikolaj Coster-Waldau. Distributed by Twentieth Century Fox.

Running time: 1 hour, 49 mins.

Parent's guide: PG-13 (sex, profanity, adult themes).

Playing at: area theaters.EndText