Except that this is not true at all, as real science that has investigated this has shown that people who are in monogamous relationships, such as marriage, have a much higher rate of satisfaction than those in polyamorous relationships. Psychology Today is hardly credible, and should never be cited, really for anything, ever. And you should probably never read Psychology Today because it will make you stupid and give you crazy ideas such as non-monogamous people are happier. Perhaps try research groups and sociologists, such as Quartz, Delia, or publications such as The Economist, or academic journals.