Well, I can give you my perspective. My wife and I are atheists. We've been monogamous for seventeen years, despite my great desire to **** other people. My wife says monogamy is easy for her. She's naturally monogamous and doesn't have any desire to have romantic or sexual relationships with others. She's a flawless monogamist. It's pretty amazing, and I respect that about her. On the other hand, I am very far from a natural monogamist. I've had painful extramarital crushes that I had to get through without acting inappropriately. I've had many, many desires to be with other women - and not just in the context of fantasy. I've really wanted to sleep with other people. Sometimes attractions have been mostly sexual - although never completely sexual, because the heart is always involved. Other times attractions have been deep and based on fundamental qualities that inspired great admiration. But through all of this, what has kept me faithful has been empathy. My wife will not agree to us openly seeing other people. She would be very hurt if I did it secretly, so I don't cheat. It's because I don't want to hurt her. I respect her boundaries and feelings of jealousy and insecurity even though I don't experience the same feelings. Sexual exclusivity isn't the goal. Being empathetic and responsible with your partner's feeling is the goal. Just don't hurt people.