Fighting equals funny in "That Old Feeling," a sort of anti-family values comedy of the adultery-can-be-fun school. But when the fireworks between Bette Midler and Dennis Farina subside for the bulk of the film, so do the laughs.

Too bad. If the momentum had been sustained, "That Old Feeling" might have been a terrific frothy farce. As it is, the film never quite lives up to its first feisty 15 or 20 minutes — and there's too much time to think about the plot's larger implications, which go largely unexplored.

Midler plays a movie star who has been divorced from novelist Farina for 14 years. And both have been married the entire time to other people — Midler to the author of psychobabble self-help books (David Rasche), Farina to a vain interior designer whose own exterior has been redesigned by plastic surgeons (Gail O'Grady).

Midler and Farina haven't seen each other for a decade-and-a-half, but a reunion is forced when their daughter (Paula Marshall) weds a pompous, conservative congressional candidate (Jamie Denton). Naturally, old wounds are opened, and Midler and Farina create a scene at the wedding reception. This makes for some hysterical exchanges, and it's quite amusing to see Marshall take them outside and punish them as if they are children.

But while Midler and Farina continue their bickering, the smoldering arguments gradually evolve into smoldering of another kind — and soon they are having sex in a nearby car. If that's not enough, they sneak away from their respective spouses that night and continue their tryst. And the next day, they run off together.

To bring them back, and prevent a scandal that might damage her husband's political career, Marshall reluctantly teams up with a tabloid photographer (Danny Nucci) who has an inside track on finding them.

Despite her over-the-title billing (and the fact that she gets to sing), this is not Midler's film. Director Carl Reiner ("Oh, God!" "All of Me") and screenwriter Leslie Dixon ("Overboard," "Mrs. Doubtfire") were apparently aiming for an ensemble comedy.

In fact, the majority of the picture seems to be about Marshall's character, and though she is OK in the role, someone a bit wackier might have lifted the energy level to a more humorous plane.

O'Grady, Rasche and especially Nucci (in a winning, nicely shaded performance) do get a few chuckles here and there, and Midler and Farina are terrific together. But the film flattens out after the first quarter and tries to skate by on the charm of the actors. The actors do have charm, but this project needed a better script.

"That Old Feeling" is rated PG-13, but it's hardly for 13- or 14-year-olds. The rating is for quite a bit of sex, raunchy sexual repartee, profanity, vulgarity and some comic violence.