Not a disaster, but close.
We have been living this life style on and off for a long time now.
I have nearly lost her once, about 10 years ago, and have had a lot of problems with her current boy friend, who has got very close to her, although things are great at the moment.
My advice to you would be to never let them be totally alone together.
In my experience, (or at least as far as my wife is concerned), she has a lot of trouble staying un emotionally attached to people she is fucking. If she doesn’t fancy them she wont fuck them. Then if she spends enough time with them, she ends up falling for them.
I have heard them whisper to each other, when they thought I couldn't hear, and in the after glow of a very good orgasm "I love you" to each other, and that hurt. If you’re not ready for that kind of thing, then this might not be for you.
Keep an eye on her phone.
If she wont let you look at it you can bet your life its because there is something on it she doesn't want you to see, and it sure as hell wont be the Christmas shopping list.
If she is using MSN to chat, keep a log of what’s said. I think if you can spot the danger signs early and pull the plug on them you might save yourself a lot of heart ache.
On the other hand you might miss out on a really good friend for you, and your lovely wife, and some very exciting times.
It’s a tough call, but one thing for sure. It wont be boring