For example - you know she is "in love" with her AP - your job is to carry on like it's irrelevant - you do your thing
1. You know she will act selfishly 2. You know she is only thinking about AP 3. She could care less if you are down or depressed - she just doesn't care 4. There is nothing you can do to snap her out of it - it's about her - not you
Feel self worth and respect yourself by living a good life with your children and show them how a real man acts with integrity and pride. Tell them she is having to work out some issues on her own and let her do her thing.
I suggest being the opposite of everything the AP Is - he obviously has low character because he is participating in causing so much pain. Some people just don't care. You are not one of those people. You honor your vows and live the best life you can. Once her bubble bursts which it will - she will look to you - the question is will you be there or will you have moved on to another chapter in your life. You can outsmart this and outlast it. Make a plan, execute the plan and be the man!!