Starring: Anson Mount, Eva Mendes, Griffin Dunne, Guillaume Canet, Keira Knightley, Sam Worthington, Stephanie Romanov

Director:Massy Tadjedin

A small-scale, indulgent but worthwhile movie from writer-director Massy Tadjedin about infidelity, jealousy and the quarter-life crisis.

Sam Worthington and Keira Knightley play Michael and Joanna, a couple who have been married around four years, and who went out for a while before that, in a period in which they broke up and got together again.

They are at a time in their lives when they are happy enough, but tormented by the realisation that they can quite easily imagine being with other people, having different relationships and being just as happy, perhaps happier. Joanna is furious to see how one of Michael's colleague Laura (Eva Mendes) clearly finds him attractive: when he goes away on a business trip with her, Joanna bumps into Alex (Guillaume Canet) the old boyfriend who appears to have triggered their brief breakup.

This is a talky film, and arguably a little exasperating, but it is targeted at grownups, and addresses the grown-up issue of monogamy: is this institution a natural state which lovers should strive for, or a wholly artificial state created to protect us from the pain and loss that must always follow from acting on our desires?

Not a perfect film, but an interesting one.