https://uberant.com/article/1353046-who-is-most-likely-to-try-wife-swapping?/

The idea of changing partners with other couples, or of having multiple partners isn’t something new. All throughout history examples can be found in numerous cultures around the globe of people and couples sharing intimate relations with multiple partners, sometimes at the same time. In Imperial China, although the Emperor was married and his wife had some very special privileges, he was able to have numerous concubines with which he could have sexual relations that would even sometimes end up in the birth of children. Moving forward thru time, the Ottoman Sultans were renowned for their harems of beautiful young women that would be available to them 24/7. Even in modern times swinging, as it came to be known, has many “practitioners”. Although not looked upon favorably by the general public, swinging is a big part of society, with more and more people annually wanting to try it and become part of a sexual and spiritual revolution.