The extend or degree of sexual stimulation among the consenting adults will oc course. Swingers will tell you that they only do whatever they feel comfortable sexually exploring with others not their own husband or wife. The swinging lifestyle and swinger clubs have been around for litterally forever. Just that now with the web and easier access they are getting more attention and perhaps drawing more would be swingers like hot females out of their closets and into the off and on premise activities that failthful swingers engage in sexually.
You of course need to be an open minded person to be able to undress and have sex with basically strangers. They do meet before hand and discuss i suppose such tings as what type of sexual stimulatio or foreplay do they like; what arouses themor turns them on; do they big or small dicks. some women actually prefer the smaller sized dicks; anyway they disucss a number of sexually tantalizing topics all sexually marked and meant for the sole purpose of pleasuring the couple and usually female swinger who would be part of the threesome or sex orgy as it were.
The couples meet at each other houses or they may have club specfically for that purpose. Men are usually not welcome especially single men, single female swingers are indeed welcome.
Swinger practices are widespread, and there are many swing resorts and vacations spots just for that all around the world.