How Do I Bring Up Non-Monogamy to my Partner?

As the term non-monogamy becomes more mainstream, (with an estimated 20% of the US population having tried some form of non-monogamy according to the Journal of Sex and Marital Therapy published in 2016) the question often gets asked, how do you bring up non-monogamy to a partner, especially that first time? Whether you just want to have a discussion and see what your partner thinks of the whole thing, or if…