I guess I am at the point now where I am dealing with a spouse having an affair. Though she has cut off the romantic part of the affair, she is still emotionally attached and is trying to be "just friends". I don't think she knows how impossible that is, so I am trying to just live my life without freaking out on her. I think I need to show I can live without her or making demands for her emotional attention before she can commit to doing her part.
When she does commit, she will realize that her friendship with the OM is destructive to all 3 of us and she will let go of him.
Here's the flaw in that logic, Bariga:
Reverse it. Because until she lets go of im, she will never realize that her relationship with him is destructive, and she will never commit to doing her part.
People caught up in affairs get addicted. Just Google "PEA" and "brain chemicals" and "love" and do some research it. The pull is INCREDIBLY strong; remember the otherwise-intelligent and levelheaded female astronaut who drove across country wearing an adult diaper, rather than take rest stop breaks, to avenge her lover in Florida??? The addiction clouds their judgment (altho it doesn't excuse it), and it blocks off their ability to receive your love deposits and to allow for you to meet any of their emotional needs.
I'm not saying you can control her -- YOU CAN'T. But there's a big difference between not controlling them, and saying "what you do is your business, and I won't ask." That smells to me like PERMISSION, and enabling, and I bet it does to her, too, especially considering your past history together.
So no, you don't corner her. But you let her know where YOUR corners (boundaries) are, and you let her know that there are consequences if she crosses them.