I myself was almost involved in a married couple, 11 years married 16 years together no children. I actually knew them for about a year, little did I know I was going through not only the beginnings of a friendship but also a very long "interviewing process". As I mentioned I was "almost" for many reasons which would take quite a long post and that's not what I'm here for.
More from YourTango: Looking For Love? It Might Be On This Singles-Only Commuter Train
Let me just tell you, their relationship was truly "open" nothing was hidden and neither partner was left at home alone at night wondering if either one was lurking bars for a one or two night stand. It was a very mutual endeavor that involved much discussion. Seemed like an awful lot of mind work to me!
More from YourTango: It's Been A While? 7 Songs That Perfectly Describe Your Love Life
I'm just going to say it seems like you are openly cheating, that is a huge difference between what you are claiming to have. Open marriages can be a very nice supplement to a healthy marriage and not to many people can take on the challenges to gain the rewards and last.