A frustratingly not-terrible action thriller.
The heart has its reasons, said the French philosopher Pascal, quoted by the American philosopher Woody Allen. It is a useful insight when no other reasons seem apparent. Connie Sumner's heart and other organs have their reasons for straying outside a happy marriage in "Unfaithful,'' but the movie doesn't say what they are. This is not necessarily a bad thing, sparing us tortured Freudian explanations and labored plot points. It is almost always more interesting to observe behavior than to listen to reasons.
Connie (Diane Lane) and her husband, Edward (Richard Gere), live with their 9-year-old son, Charlie (Erik Per Sullivan), in one of those Westchester County houses that has a room for every mood. They are happy together, or at least the movie supplies us with no reasons why they are unhappy. One windy day she drives into New York City, is literally blown down on top of a rare book dealer named Paul Martel (Olivier Martinez), and is invited upstairs for Band-Aids and a cup of tea. He occupies a large flat filled with shelves of books and art objects.
Martel is your average Calvin Klein model as a bibliophile. He has the Spanish looks, the French accent, the permanent three-day beard, and the strength to suspend a woman indefinitely in any position while making love. He is also cool in his seduction methods. Instead of making a crude pass, he asks her to accept a book as a gift from him, and directs her down an aisle to the last book on the end of the second shelf from the top, where he tells her what page to turn to, and then joins her in reciting the words there: Be happy for this moment, for this moment is your life.
Does it occur to Connie that Martel planted that book for just such an occasion as this? No, because she likes to be treated in such a way, and soon she's on the phone with a transparent ruse to get up to his apartment again, where Martel overcomes her temporary stall in bed by commanding her: Hit me! That breaks the logjam, and soon they're involved in a passionate affair that involves arduous sex in his apartment and quick sex in restrooms, movie theaters and corridors. (The movie they go to see is Tati's "Monsieur Hulot's Holiday'' which, despite its stature on my list of The Great Movies, fails to compete with furtive experiments that would no doubt have Hulot puffing furiously at his pipe.) Edward senses that something is wrong. There are clues, but mostly he picks up on her mood, and eventually hires a man to shadow her.