No, unfortunately “throuples” is not something one orders at a restaurant and goggles down – that is truffles. No, throuples are three people in a sexual relationship, or polyamory. Polygamy differs, it is said, and involves multiple partners in a marriage.
https://www.dailytelegraph.com.au/lifestyle/relationships/throuple-consisting-of-chris-and-matt-brandt-and-cait-earnest-open-up-on-unconventional-relationship/news-story/c8a7b77ebeca442f04c6f094b01c55e5
There will now be a movement towards polygamy, based on the need to accommodate Muslims. In fact, it is already underway:
https://billmuehlenberg.com/2016/12/15/islamic-polygamy-rapidly-expanding-west/
Welcome to the slippery slope that we are now on from the same sex vote. Australians are set to learn the hard way, if they can learn anything at all:
https://billmuehlenberg.com/2017/11/18/homosexual-marriage-always-trumps-religious-freedom/