You'll get to a breaking point at some time in the future where you'll say you're done with her, and the question is if she's going to come back before that happens.
My breaking point is whenever the relationship becomes physical. It may have already become so...I dont know and may never know.
And we werent married, just engaged and living together...so I really have no power to say I wont live in any sort of open relationship. Essentially we are like a couple thats already divorced. So we are done pretty much unless the OM treats her so horribly that she wants to get away from him...and he does seem to be a predator with excellent conversation skills...so I'm probably out of luck.