I think a good part of this is listening really well and validating what is being said by the WAS. They expect us to defend the relationship. We want to. Part of the affair dynamic is having something to push against. It helps create the intensity of the feelings. If you go in the direction that they push and don't push back they are off balance. Think of it as emotional aikido! Use their momentum against them by doing the opposite of the reaction they are trying to get out of you. Eventually, you might even use this to proactively change their world.

I think also GAL and moving on says this through actions. It says that I'm moving on and I accept this situation as it is and I'm moving on. The cheating spouse has so much self esteem tied up in external validation that they don't want to lose you, no matter how much they say they do. If you make them pursue you to get you to resist them leaving, you gain an advantage.

“No problem can be solved from the same level of consciousness that created it. ”
– Albert Einstein