text: I think it is because people have a lot of hang ups about sex in the US.  So many people directly associate sex with love and assume you have to be in love with someone to have good sex with them.  Personally, I think that sex is one of the most fun things a person can do and I'm sure most people agree.  I also think that it is very personal and I'm not into sleeping with just anyone.  But I think that sex between 2 (or more) people that get along and have a good time together but are not in love, is perfectly fine.  I also think that it is a natural desire for most people to be want to have sex with more than just the one person you are in love with, especially people who are comfortable with sex.  My boyfriend and I have tried swinging with other couples and we have enjoyed it.  We both trust each other and know that it is just about having fun.  Plus, I feel more confident that my boyfriend isn't going to cheat on me because he has an outlet for his natural feelings to be with other women.  Just my opinion!