Adultery for Beginners — Sarah Duncan

Isabel and Neil are old marrieds. Suburban old marrieds, at that. While the routine that's as comfortable as an old shoe seems to suit Neil just fine, Isabel--professional wife and mother and one the nicest women in the line at school pick-up--is restless. Tired of being just "Neil's wife" or "Michael's mommy", she takes a part-time job working for the disorganized but devastatingly attractive Patrick, only to find herself drawn to him. Despite telling herself to think of her husband and children, Isabel finds herself doing the unthinkable, and plunging into a world of conflicting loyalties, desires and responsibilities.