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.

The secret to desire in a long-term relationship

People grow up learning to be silent about their sexuality, so where are they going to learn to talk about it when they are in a relationship? Shame, guilt, ignorance, reservation, prudishness, all kinds of different cultural systems and social stereotypes shroud sexuality in secrecy and in silence. And there's the romantic notion. "If I say in the beginning, that I am missing something, you are instantly going to think that means you are not enough."

If a woman isn't feeling sexual with herself, she won't respond to advances from any partner, male or female. When this woman goes dancing, she's finding a connection with her own erotic self. It might be about being on a dance floor, feeling free, not having to feel at all responsible for anybody else's well-being. For other people, it might be about going on a hike for four days by herself and reconnecting with nature and strength and endurance and beauty.

Secrecy fuels erotic intensity because it makes you feel like you're doing something that is entirely yours. It gives you the sense of autonomy, the sense of freedom, and the sense of sovereignty. And then you add to that the sexual energy. In many affairs, people will tell you they slept with the person three or four times, but the story went on for months. That's an important thing because many people who have affairs often have very good sexual relationships at home. It's not necessarily a compensation story. But affairs offer a different sexuality with a different context.

In committed sex, in marriage, people don't feel the need to seduce or to build anticipation - - that's an effort they think they no longer need to do now that they have conquered their partner. If they're in the mood, their partner should be too.

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.