You are so right. I can make decisions too rather just waiting to see what he is going to do. But I guess I am really worried about it coming to the decision to leave. But I don't have to make that decision right now. I need to remember that.
Correct. And you also need to remember that if YOU decide to let him go (leave) over HIM violating one of your core boundaries, then staying wouldn't have been an option anyway, kwim? I mean, if you really WON'T live in an open marriage, and he won't end the affair, and you draw that boundary and he crosses it, then staying in that kind of situation wasn't a viable option for you ANYWAY, right?
Your own integrity, happiness and health is more important to you than the marriage.
Now . . that doesn't make ANY of that any EASIER, but it does add CLARITY, I think.