“What does exclusivity mean to you?” asks Amy Hart, a contestant on UK reality TV show Love Island in 2019. Her partner, Curtis Pritchard, is cornered and she knows it. He had been kissing other girls behind her back. Pritchard shrinks into his seat as Hart eloquently and calmly lists the issues with their relationship, starting with how he could possibly have romantic feelings for two people at the same time, how she needed him, and how he had let her down.
Hart was operating under the assumption that a romantic relationship involves two people only, and that Pritchard was breaking the rules. But what we know about human relationships is that historically, they were much more complicated than the monogamy that is normal in many societies now. Might we return to our non-monogamous roots?
Consensual non-monogamy (CNM) allows both parties in a couple to be free to explore relationships with other people. This could incorporate everything from polyamory to the swinging and other forms of “open” relationship. Regardless of the form it takes, one of the defining features of CNM is that partners discuss and agree on the boundaries, such as how far they can go, and when and where. This definition means that Pritchard’s antics wouldn’t come under this banner, as Hart had not signed up for them. But the presence of non-monogamy in a sizeable minority of the population might explain why Pritchard acted the way he did.
Despite the prevalence of monogamy, humans are pretty obsessed with having sex with people other than their partner. Psychologist Justin Lehmiller asked 4,000 Americans to describe their sexual fantasies for his book Tell Me What You Want. Having a threesome is the most popular fantasy, by some margin. And what is a threesome if not consensual non-monogamy?
“If we think about all the people in relationships, about 5% would define as CNM,” says Amy Muise, assistant professor of psychology at York University in Toronto, Canada. But including those who have tried CNM boosts the figure. “In lifetime experience, 21% of people have been non-monogamous at some point.”
Having a threesome is the most popular sexual fantasy, by some margin…