Monogamy existed only for a short period of time in human histor

it may be marginalized in 50 years or sooner (marriage rate <50% in europe now). you could have many mates if you were born 10,000 years ago, or 100 years later, without any social pressure.

The authors of <<Sex At Dawn>> strongly condemn monogamy from an ethical perspective, as we condemn the Middle Age. 

不让得不到满足的一方出轨，也同样是不道德的?