An admiration of vigour and youthful exuberance strikes a chord in Prime, a romantic comedy about a 37-year-old divorcee and a 23-year-old hunk, hoping that love at first sight can bridge the sizeable age gap.

At first, red-hot sexual attraction blinds the two lovers to the fissures that gradually appear in the relationship, even with friends and family warning of impending heartache.

Cultural differences and questions of religious faith, and a distinct lack of shared interests, also threaten to derail the fledgling romance.

But isn't love supposed to conquer all?

Writer-director Ben Younger creates further conflict between his mismatched lovebirds with a dramatic contrivance: the divorcee is personally connected to her beau's mother.

This frank dissection of modern dating rituals, and the pursuit of love in a global society where appearances matter, gradually runs out of steam.

Younger hesitates about the fate of his central twosome and, as he treads water, we lose interest despite sparkling performances and some great one-liners.

Non-practising Catholic, Rafi (Uma Thurman), recovers from the devastation of her failed marriage by throwing herself into her work in the fashion industry.

Romance blossoms unexpectedly when she meets David (Bryan Greenberg), who lives with his grandparents and hides his burning desire to become a painter from his strict Jewish parents.

Rafi enjoys the no-ties thrills of a relationship with a younger man... until she realises that David is the son of her uptight psychoanalyst, Lisa (Meryl Streep).

Prime is a witty if unfocused portrait of a May to December romance, which benefits greatly from lively performances from Thurman and Streep.

Both actresses are blessed with impeccable comic timing and Younger gifts them some wonderfully sparky dialogue, especially in their sessions together.