YouGov’s latest research shows that, overall, the vast majority of Americans (68%) would in no circumstances be OK with their romantic partner engaging in sexual activities with someone else. At the opposite end of the scale 5% would be OK with it, while 19% say that it depends on the circumstances. Most young Americans (56%) also outright reject anything other than strict monogamy, but this is lower than any of their elders.

This difference in attitude can be seen in people’s experience. Overall, 11% of Americans have had sexual contact with other people with the consent of their partner, while 19% have had sexual contact without their consent. While the self-reported rate of cheating changes little according to age, younger Americans are much more likely to report having had sexual contact with other people with the consent of their partners. 17% of under-45s say that they have, compared to only 3% of over-65s.