One-third of Americans say their ideal relationship is non-monogamous

Many Americans aren’t head over heels in love with the idea of monogamy.

A January poll of more than 1,300 US adults finds that about one-third (32%) of US adults say that their ideal relationship is non-monogamous to some degree.

Millennials (43%) are particularly likely to say their ideal relationship is non-monogamous, though an equal percentage (43%) of this generation says that their ideal relationship is completely monogamous.

YouGov’s data suggests that Americans as a whole might be gradually warming up to the idea of non-monogamy.

When asked in September 2016 about their ideal relationship, 61 percent said it would be completely monogamous. In January 2020, that number has dropped slightly, to 56 percent.

Many Americans are already in non-monogamous relationships or marriages.

Among US adults who are in a relationship, 23 percent say their current relationship is non-monogamous to some degree. About three in 10 (31%) Millennials in a relationship say their relationship is non-monogamous. Of this group, 8 percent define their relationship as “completely non-monogamous.”

While many adults aren’t in a non-monogamous relationship currently, they may still have some experience being with other people outside of their primary relationship.

Roughly one in eight (12%) US adults says that they have engaged in sexual activity with someone else, with the consent of their main romantic partner. But slightly more (18%) say that they’ve had a sexual encounter with someone else, without their partner’s consent.

Men (23%) are considerably more likely than women (13%) to say they’ve had sex with someone else, without the consent of their main romantic partner at the time.

When asked about how they would feel if a partner came to them wanting to engage in sexual activity with someone else, most Americans (67%) say they wouldn’t be okay with this. Just 6 percent say that they would be okay with this, while 17 percent say their comfort with this would depend on the details of the situation.

Millennials (56%) are less likely than members of Generation X (69%) and Baby Boomers (74%) to say they would not be okay with this under any circumstances. Just over one in five (22%) Millennials chose “Whether or not I am okay with it depends on the situation,” while 9 percent said they would be okay with it.

See full survey results here, and full results from the 2016 survey here.

Related: Most Americans believe in soulmates

Methodology: Total unweighted sample size was 1,342 US adults. The figures have been weighted and are representative of all US adults (ages 18+). Interviews were conducted online between January 6 - 7, 2020.