Through interviews with married women of various ages who have had affairs, Heyn, a Mademoiselle columnist who's worked in women's magazines for 20 years, takes a fresh look at female adultery-- which she claims is on the rise--and attempts to explode some common beliefs about women and sex (among them, that women are monogamous by nature and that happily married women don't have affairs). Without claiming to have conducted a scientific study, Heyn draws on anecdotal material that seems to point to a new insistence on sexual pleasure for married women--whether achieved within the marital framework or outside of it. Most of the women queried acknowledge burying their sexual past when they got married and buying into what Heyn calls ``the myth of romantic marriage.'' Victims of a ``Donna Reed'' syndrome--trying to be the perfect wife--they begin to experience a loss of self. Eventually, given the opportunity, they attempt to regain their individuality in sexual affairs. Generally, these affairs empower and revitalize the women--who have no regrets. What's groundbreaking about Heyn's survey, then, is its indication that women are less willing today to sacrifice their happiness for an ideal (i.e., a monogamous marriage) that, at least in these cases, doesn't fulfill their needs. Women apparently can love two men at once, and they can love their spouse and have sex with someone else, just as men allegedly do. And an affair can act as a catalyst for positive change. What makes this book less than revolutionary, though, is that, taken one by one, something seems to be missing in the way these married couples relate to one another. And so, based on Heyn's study, one can't generalize about the limits of monogamous marriage; but one can conclude that women are less willing today to barter sexual happiness for the security of marriage. They want both. While Heyn never quite develops a coherent thesis, then, she does give appealing voice to a growing and significant phenomenon in American female sexuality.