"Prime" has a number of things going for it that many romantic comedies these days lack. It features a new permutation on the old mistaken-identity plot: 37-year-old divorcée Rafi (Uma Thurman) starts dating carefree 23-year-old David (Bryan Greenberg), neither of them realizing that he is the son of her therapist Lisa (Meryl Streep). There are moments of real wit, the love story is charming without being sentimentally cloying, and the film takes a pleasingly mature, realistic approach to romance.
However, "Prime" also makes many wrong turns along the way. It's never sure how deeply it wants to explore the serious issues raised by its plotage differences in relationships, inter-religious dating (David is Jewish), and the ethics of Lisa continuing to be Rafi's therapist. Sometimes, it treats these themes with seriocomic intelligence. At other times, it ignores them in favor of sitcom humor involving David's jerky best friend or Rafi's gay co-workers.
"Prime" eventually becomes David's story, focusing on how dating Rafi helps him mature. But this often seems like the wrong choice. Cheerful David is the least conflicted of the three main characters, and Greenberg, while a competent actor, doesn't have Thurman- or Streep- level charisma. Thus, even though this clearly wasn't the intent, many David-centered scenes feel like padding. The best parts of the movie are the scenes between the two actresses: Streep's awkward, pained reactions as Thurman glowingly describes her new boyfriend are priceless.
