On some level we trade passion for security, that's trading one illusion for another. It's a matter of degree. We can't live in constant fear, but we can't live without any. The fear of loss is essential to love.

I believe that the vast majority of people that are unfaithful are monogamous in their beliefs. The ones who are not monogamous in their beliefs either live in poly relationships or consensual non-monogamous relationships, or they have divorced. If it's very bad, then people don't stay married these days in the West. They can be married and have their family, but they want something else - they want something that they don't have in their lives, or simply to be someone that isn't who they are in the context of their marriage.

There is not one person who can fulfill all your needs. You may choose a partner who is your intellectual equal, and he may not be your most compatible sexual partner. And then there's the duality between security and adventure. A relationship that gives you plenty of novelty, and adventure, may not provide the stability you long for. Time, continuity and familiarity with somebody gives you other things in life but won't necessarily give you the kind of intense lustful experiences that you may have when you first meet someone and are curious about penetrating the mystery of them.

Even a good marriage leaves people with longings for certain things their marriage will never be. So, do they accept that, make compromises, and say, "You can't have everything in life," which is what we always did? Or do they say, "I deserve more. I want to experience that thing and, you know, I have fifty more years to live than I used to." It's not necessarily that we have more desires today, but we do feel more entitled to pursue them. We live in this "right to happiness" culture, and yes, we do live half a century longer than we used to.

Our consumer economy peddles the notions "romantic consumerism" of finding "the one," of being the one. It's the narcissistic enhancement of, "I'm the one you stopped your nomadic life for." It's one thing when you have sex for the first time when you marry, but it's another thing altogether when you stop having sex with others when you marry. So the marital commitment becomes, "I must be really special. With me, you no longer think you can find better next door." Romantic consumerism is thinking you can't find better, younger or newer.

The very ingredients that nurture love - mutuality, reciprocity, protection, worry, responsibility for the other - are sometimes the very ingredients that stifle desire.

For some people, a one-night stand doesn't make any difference in a seven-year love affair. I don't believe the degree of betrayal is always commensurate with the egregiousness of the behavior. They are two separate things.