May (Anne Reid), the sixtysomething suburban grandmother who falls for a man half her age in the subversive British sudser The Mother, will never be photographed with Demi Moore, Diane Lane, or Susan Sarandon in glossy-magazine trend pieces about the sexiness of older women with younger men. May is a little lumpy, a little dowdy, and while her husband is alive, she wills her sack-like self into a posture of forbearance. When the two senior citizens visit their grown children (and uninterested grandchildren) in London, they're bewildered by the yuppie din of the city. And director Roger Michell (''Notting Hill'') conveys some of the sharpest insights into the woman buried beneath the wife and mother in those early scenes, using ragged, vérité-style camera work that takes merciless inventory of a certain stripe of posh, hard-edged modern family life in which dowdy grannies are invisible.
It's when her husband dies of a heart attack that May blooms -- to her own violent surprise. ''Why shouldn't I be difficult?'' she snaps at her distracted, workaholic son, who wants to deliver her into uncomplaining widowhood. Why indeed? ''The Mother'' is written by ''My Beautiful Laundrette'''s happy-to-be-naughty Hanif Kureishi, offering up a few too many carefully folded lines of dialogue. May not only falls into a hot sexual liaison with the muscled bloke renovating her son's house (''Sylvia'''s Daniel Craig, worth liaising with) but also admits that she was good and sick of being a wife and mother and sometimes hated her children.
Perversely, as the story shifts from one of casually observed household disarray to the more ''shocking'' story of one older woman's sexual appetite, the picture shifts to a more self-conscious pace and style. Reid, though, is a discovery -- as believable and naturally sexual an older woman as Joan Collins is a caricature of one. A familiar British TV player less known in the U.S. (Wallace and Gromit specialists may recognize her voice as that of Wendoline in ''A Close Shave''), Reid embodies the sense of feminine permission that's also a part of May's name.