摘自Wiki：
Swinging, also known as wife swapping or partner swapping, is a non-monogamous behavior, in which both singles and partners in a committed relationship engage in s*xual activities with others as a recreational or social activity. The phenomenon of swinging, or at least its wider discussion and practice, is regarded by some as arising from the freer attitudes to s*xual activity after the s*xual revolution of the 1960s, the invention and availability of the contraceptive pill and the emergence of treatments for many of the s*xually transmitted diseases that were known at that time. The sw***er community sometimes refers to itself as "the lifestyle", or as "the alternative lifestyle". The term "wife swapping" or "partner swapping" is criticized for not accurately describing the full range of s*xual activities in which both singles or couples may engage, which is not limited to conventional s*x with a person other than their regular s*x partner. Other terms sometimes encountered are wife sharing, partner sharing, wife trading and wife lending, which describe similar concepts, usually in sociological or anthropological research. As these terms have become dated, with women participating as fully in the decision making process as their male partners, the more gender-neutral term "swinging" has gained popularity. via: http://en.wikipedia.org/wiki/Swinging_%28s*xual_practice%29
