btw, one of the best I ever saw on this forum at doing this was a poster named Pearlharbor. She wasn't married, but was in a long-term, and she-thought MONOGAMOUS relationship with a guy, who then cheated on her. Once she decided what it was she wanted and needed, she just kept calmly and firmly telling him "This is what I need from a relationship. Whether or not you can do this is entirely up to you, but I felt it only fair to let you know what it is I'll need going forward."
She was amazing. I'm sure you could still find her old posts on here somewhere.
