Swingers' events generally welcome couples and single females, but not single males.  And while couples may develop friendships with other couples at these events, these friendships are generally not pursued outside the swinging venue.  So, in polyamory, the emphasis is on emotional intimacy and sharing; in swinging, the emphasis is on sex as play and entertainment, and relationship development is not strongly encouraged.
 
            Just as there are many varieties of polyamory, swinging can take many forms, as well.  Among couples who are new to swinging, there may be an agreement that they will not engage in sexual activities with others, but they will observe and allow others to observe them (known as "soft" swinging).  As their comfort level increases, they may decide to try some other forms of swinging, such as "soft swap", or oral sex with another partner.    Couples may continue to explore and negotiate new activities, for example, whether a partner may engage in activities when the other partner is out of the room, or whether to allow full penetration ("full swap").  It is common for couples to set certain absolute boundaries when swinging, such as using a condom, or reserving kissing for one's partner.
 
            When it comes to understanding and describing human sexual behavior, there is an entire spectrum and it is difficult to describe people in very simplistic terms.