Virtually all men fantasize about having two girls, and many women admit to fantasizing about sex with two men.
Adult Swingers, as each generation enters sexual maturity, with less sexually repressed attitudes, they are increasingly willing to experiment.
As information becomes more freely available via the Internet, more and more couples talk about it and decide to give it a try.
Most swingers have a story about just such an occurrence.
It usually goes something like this: "My wife and I go to swinger's parties often and one party we went to was great -- until our neighbor and his wife walked in.
The man at the grocery store who looked your wife up and down may not just be thinking about her being naked - he may be thinking about her being naked with his wife.
While most swinging is about two couples sharing fun and swapping partners, many swingers regularly participate in threesomes.