I'm curious too. What's the longest-term open relationship anybody has ever been in? Mine was just a couple of years, and ended .... well, it ended badly, to say the least. In our case, the "open" part of our relationship was a symptom of problems that we had properly clicking together. Very different people indeed
But here in Seattle I've heard rumors of folks that have managed it. Anybody here managed an actual long-term open relationship?