Many couples choose to remain unmarried seeing marriage as artificial.
A couple may feel they want to be with each other permanently because they love each other, not because they have a legal document saying they are married. Swinging is an example in which you share sexually with others as a couple where you still have one primarily relationship. Avoids the cheating that often occurs in monogamy and encourages open communications. Many couples find their prime relationships enhanced by the honest sharing of variety and being open with their partners, enjoying hearing about each other's feelings and experiences with other intimate partners. Our problem with stereotypical swinging is that it is often about brief sexual thrusting for pure pleasure with a large number of partners.