I didn't want to force the discussion by bringing up my own opinions in the first post, so thanks for sharing yours, rj. What was it that ultimately made you decide against it?

I've done it a couple of times, with good friends of mine. Each time I was the "guest" - they are a couple that have been dating for a long time, and I enjoyed the experience and I would say it made me closer to both of them. However, I'm not sure how I would feel about doing it with someone that I'm actually in love with - I don't know how I would react to seeing him with another girl.