Secrecy is the number one organizing principle of an infidelity. An affair always lives in the shadow of the primary relationship, hoping never to be discovered. The secrecy is precisely what intensifies the erotic charge. “Sex and subterfuge make a delicious cocktail,”7 writes journalist Julia Keller. We all know from childhood the glee of hiding and keeping secrets. They make us feel powerful, less vulnerable, and more free. But this dark pleasure is frowned on in adulthood. “I’ve always been a what-you-see-is-what-you-get kind of person,” says Angela, a punctilious Irish American paralegal who realized, through her affair with a client, that she enjoys sneaking around. “Discovering that I could act in total breach of my own long-held values was both bewildering and exciting at the same time. Once I was speaking with my sister, who was rattling away about the wrongdoing of cheaters, all the while smiling inwardly at my own secret. Little did she know that she was looking into the face of the ‘villain.’”

These stories make a critical point—many affairs are less about sex than about desire: the desire to feel desired, to feel special, to be seen and connected, to compel attention. All these carry an erotic frisson that makes us feel alive, renewed, recharged. It is more energy than act, more enchantment than intercourse.

Emotional involvement is the third element that may play a role in infidelity. Most affairs register an emotional component, to one degree or another. At the deep end of the spectrum we have the love affair, where the accompanying bouquet of passionate feelings is integral. “I thought I knew what love was, but I have never felt like this before” is a common refrain. People in this state talk to me about love, transcendence, awakening, destiny, divine intervention—something so pure that they could not pass it by, because “to deny those feelings would have been an act of self-betrayal.” For those involved in such an unparalleled love story, the term “affair” is inadequate, for it doesn’t begin to capture the emotional depth of the experience. “When you call it cheating, you reduce it to something vulgar,” Ludo says. “Because she had gone through something similar, Mandy was the first person with whom I’ve ever been able to open up about my father’s abuse. Yes, we had sex, but it was so much more than that.”

It’s not the first time I’ve heard such a tale of role reversal and judgment turned into justification. When it comes to infidelity, like most things in life, human beings commit what social psychologists call the actor-observer bias. If you cheat, it’s because you are a selfish, weak, untrustworthy person. But if I do it, it’s because of the situation I found myself in. For ourselves, we focus on the mitigating circumstances; for others, we blame character.