Mr Naughty Girly here.....
Just thought I would add another perspective here.
I see the majority of people here "condemn" (maybe not the right choice of word, but I'm sure you get my drift) what me and my other half have been up to, but there are some important things that you guys are missing.
You only ever hear of the relationships that 3ways have broken up. How many of your friends do you think would tell you that they were thinking of or had had a 3way? Not many. I know this, because we havnt told anyone either, It is quite a taboo subject. You will only hear about from your friends if it did go wrong and was the cause of the break up of the relationship.
Now for us, this was quite an experience, one we will probably repeat. It was her idea in the 1st instance, and being a bloke I would not say no lol! We have been together a very long time, and had a very active sex life, and this is just an extension/progression of that sex life. All the way through we were VERY aware of eachother, and how the other was feeling. There were "signs" arranged to tell the other if they felt funny, jealous, awkward etc, and this made it more relaxed as we both knew that the other was ok, and if not we knew what to do to make it ok. Fortunately, the signs were all positive and we had a really good time.
Half the reasons for the relationship breakdowns mentioned in previous posts, as far as I can see, are all down to the man wanting to stray anyway, "I want a threesome" says he, and "with your best friend", the real translation of that is "I want to have sex with your best friend". Of course a threesome in that instance is going to result in a relationship breakdown. People venturing down that route, I agree are destined for problems.
I don't believe that our situation is unique, I believe there are many other couples out there whos relationship is strong and can actually benefit from things like this. Since we started down this route, we have spoken with many couples in a similiar positions, who are still happy, still together and still playing. How many of your friends could be "one of those" couples? I bet you know at least one couple who are doing this kinda thing and you have no idea that they are.
And for what its worth, I see no difference between this and swinging.
I hope that this has helped a few of you see our perspective, its not always a bad thing..........