I agree with MyRose, these things are best with people who all have a neutral relationship with each other, and are looking for an intense experience. My experience with multiple partners is that the more planning you need, the less interesting the engagement becomes. My first was at a normal party (as opposed to a swingers party) and was fantastic and unexpected. My second was with a friend who was trying to seduce her coworker and thought a threesome was a good intro. I had fun, but it generated a lot of unnecessary drama. After that, I avoided anything that required planning. If everyone is in the mood for it at the same time it will work. Less opportunity for each person to bring nervousness and fear into the fun.