The iconic couples therapist and bestselling author of "Mating in Captivity," Esther Perel, returns in paperback with a provocative look at relationships through the lens of infidelity. An affair can rob a couple of their relationship, their happiness, and even their identity. Yet this extremely common human experience is so poorly understood. What should we make of this age-old taboo—universally forbidden yet universally practiced? Why do people cheat, even those in happy marriages? Why does an affair hurt so much? When we talk about infidelity, what exactly do we mean? Do our romantic expectations of marriage expose us to betrayal? Is there such a thing as an affair-proof marriage? Is it possible to love more than one person at the same time? Can an affair ever help a marriage? Perel weaves true case stories with insightful psychological and cultural analysis in this fast-paced and captivating book.