Polygamy, Monogamy, and Polyandry
Polyandry (a woman having multiple husbands) occurs very rarely in a few isolated tribal societies. These societies include some bands of the Canadian Inuit, although the practice has declined sharply in the 20th century due to their conversion from tribal religion to Christianity by Moravian missionaries. Additionally, the Spartans were notable for practicing polyandry.
Societies which permit group marriage are extremely rare, but have existed in Utopian societies such as the Oneida Community.
Today, many married people practice various forms of consensual nonmonogamy, including polyamory and swinging. These people have agreements with their spouses that permit other intimate relationships or sexual partners. Therefore, the concept of marriage need not necessarily hinge on sexual or emotional monogamy.
Read more about this topic: Types Of Marriages