A mild but diverting dip into extramarital adventure. Lee MacDougal, a faculty wife and mother in upstate New York, is married to art historian Walter--whose basic nature is snug as a bug in a rug and hardly designed to take a wife's infidelity with anything resembling grace. And he doesn't: when Walter finds out (by way of a third-party snitch letter) that Lee has been getting it on with colleague Victor in Victor's farmhouse (on mornings when the girls are at the Montessori school), Walter cuffs himself up into a nice cozy flip-out, requiring hospitalization. Lee, contrite, realizes, after Walter's release, that ""We can never be babes-in-the-woods again, holding hands against the dangers of the night. The horrors and dangers have slipped in the door when we weren't looking and now will occupy the bed between us."" On the other hand, however, she's not altogether sorry for her escapade: the risk was liberating. In a clean and relaxed style, Robertson renders this by-now-clichÃ‰d story into something generally likable. . . even as it evades more real issues and feelings than it faces, using wry humor as a defense. All in all, the geniality here almost makes up for the weightlessness.