By this I think they mean “ethical non monogamy” in the US? People have been screwing around on their partners throughout history. Some cultures turn a blind

By this I think they mean “ethical non monogamy” in the US? People have been screwing around on their partners throughout history. Some cultures turn a blind eye so long as proper discretion is exercised. In others, polygamous marriages are explicitly sanctioned - usually to the detriment of women. The US tends to be a bit puritanical when it comes to sex.