is that learnt from bitter experience of the swinging scene?"
Not at all Guest. I have known three couples who got involved with it. All three have had their marriages destroyed. It's one of those things that look good on paper--but don't work out all that well for most people. Sorry about the 'stern stuff'. Some issues--particularly ones in which I see someone about to do something really stupid--get my hackles up. This type of thing is one of 'em. If the writer has to ask, then he and she haven't agreed on the substance of the issue. IMO, their marriage will not survive the games.
For other people, it's something they incorporate into their lives and it's OK with them as a couple. That's cool by me, too. I am not making a moral judgement; I am making a call from what I have seen happen to others. Truthfully, it's none of my business. However, after it's posted, it becomes my business--just as it becomes everybody else's.