They are referred to as swingers, it's a lifestyle. Most are married couples although some places accept singles. Ages usually in 30-50 yr range. It is not a common thing for young people to participate. Not a right or wrong to it, rather just a preference.
I went to an orgy once, its fun but can leave u feeling a little hollow. Well from my experiance anyway, depends how often you are having empty sex. Im going off point, it is wild and its natural to enjoy your sexuality while you are young, save the seriousness for somebody worth being serious about. If they're are your soul mate, or close enough, they'll accept you swang in the past, and hey, if you really liked it you both might want to carry it on!
Boy that's a nice thing to meet people for, if you like Sex. My wife and I do. She loves to have sex with others, and I like to watch her doing it. Sometimes I will join in, but my biggest turn-on is watching her enjoy her fun. She is extremely beautiful with long Auburn hair and a young girls figure, so she is quite a turn-on to most everyone. I know she is to me, and we enjoy our sex. We don't like it with groups, but like just 3 of us when we have our sexual feasts, but they do sometimes last a whole weekend. She enjoys it for tremendously long periods of time, and I wind-up having 8 or 10 orgasms just watching her enjoy herself during a weekend. Of course I participate sometimes myself when it's so exciting I can't help myself.
Be free mofo