THERE are several reasons for taking a lover. If you're in your 40s and a little overweight it's a valuable way of shaping up (for everyone knows regular illicit dalliance makes the pounds fall away). If it's 245 days since you last had sex with your husband it might well be a human-rights issue. And then, if an absurdly seductive Russian starts wooing you with elaborate and exuberant compliments - well, you'd be mad to resist.

Thus reasons Chloe Zhivago, psychotherapist, mother of two, an apparently contented and successful woman. Until recently, her life has followed the broad and primrosy path towards happily ever after. But, as she remarks, there comes a time when a man can look at a woman without seeing her and a woman can look at a man and see straight through him. At this moment her story begins. . . and off it goes with a bang.

She decides to grasp her hunk of an opportunity with everything she's got (once she's had it all exfoliated, mown and polished). Her phone becomes red-hot with titillating textual intercourse, a rendezvous is arranged and the affair with Ivan, pronounced Eevahn, begins.

Olivia Lichtenstein's first novel is full to bursting with good things. Parodying a prevalent practice, she often opens a chapter with a recipe. One or two sound delicious; others - recipes for trouble, for adultery, for humble pie - are more sinister.

Chloe may fudge the issue of fidelity but she knows the golden rules of contemporary womanhood - that no one should stand in the way of a child who voluntarily eats fresh fruit and/or vegetables and that you'll burn in hell if you fail to remove your make-up at night.

Lichtenstein's writing is succinct, witty and often funny enough to make you hoot on public transport. Some characters - particularly Chloe's father and her children - are carefully cross-hatched in fine and touching detail; others are drawn in broadly comic charcoal.

Amongst these are Bea, the warrior lesbian au pair; Janet, the anxious and anorexic cat;

Ruthie, the worldly best friend who can't quite quit the coke habit; and Edie, the mother-inlaw from an Irish Methodist family, who eschews all drink save Bailey's, which she considers non-alcoholic and consumes by the crateful.

Chloe's husband Greg is a handsome, hypochondriac GP who hates ill people, is too vain to wear glasses and is locked in mortal combat with traffic wardens. Terrified of early-onset Alzheimer's, he hides everyday objects in ludicrous places to challenge his memory, and his family's patience. He is comically and transparently himself, and as such is ultimately irresistible.

The craggy cardboard Ivan proves no match for the unlikely hero of this accomplished, enjoyable and surprisingly moral fable.