Uma Thurman as Mrs. Robinson?

Meryl Streep mines unexpected pathos in a comedic role as an overbearing mother.

This must be the season for older-meets-younger romances. Last week we had "Shopgirl," where Steve Martin woefully wooed Claire Danes. Now we have "Prime," a comedy written and directed by the aptly named Ben Younger, which has Uma Thurman's Rafi, 37 and recently divorced, lusting after Bryan Greenberg's David, 23 and living with his grandparents. It's a relief having the woman be the older one for a change, but there's an even bigger twist: Rafi's therapist, Lisa, played by Meryl Streep in beads and bangs, is, unknown to her patient, David's mother.

Younger's first feature was the bracingly acerbic "Boiler Room," about sub-Wall Street scroungers, that looked like it was fueled by 90-proof testosterone. "Prime" is a much lighter and more farcical affair.

Just in case we didn't think that the age differences here were enough of a roadblock, Younger also plays up another angle: Rafi is Catholic and David is Jewish. His family, especially his mother, are dead set against his dating anyone outside the faith. But since neither Rafi nor David are particularly religious, this conflict doesn't really add much to the mix.

It's just an excuse for a lot of Yiddish-mama shtick, although Streep, who seems to have found a new lease on life as a loosey-goosey comedienne, does more with it than might have seemed possible. The scene where she guesses the identity of Rafi's lover is a classic - alone in her office, horrified, she reverts to deep breathing exercises and yoga and makes it look like heavy calisthenics.

Lisa's attempts to control her son are really expressions of love. (This is what gives Streep's performance its dollop of depth). The love that builds between Rafi and David is a bit more complicated. Because he doesn't fully characterize either of them, Younger makes us see their relationship as doomed by age and circumstance.

David, for example, is a talented artist but we never really hear him talk about what inspires him. And Rafi, whose desire for a baby is ticking away, doesn't talk to him very often about her deepest concerns. There are a few moments when their age difference is tartly summarized: She is stunned that he had never heard of John Coltrane; he would rather play Nintendo than have sex. But not much is made of the allure of those differences. Most of the time we're left with the usual wink-wink stuff about a younger man's prowess.

Frankly, the most disturbing thing about "Prime" is that Uma Thurman is now officially an Older Woman. Grade: B-

• Rated PG-13 for sexual content including dialogue, and for language.