Q&A Am I Using the Affair Partners Choices as a Cop-Out?

I ceased all contact with the affair partner nearly one year ago. My wife and I have gone through individual and marital counseling, EMS Weekend, and we are finishing Married for Life. I have no lingering feelings - either love or hate - for the affair partner. As I have gained more perspective about the affair and have learned more about the psychology of what I was experiencing and the affair partner was doing, I have felt more bitterness toward the affair partner. I feel I was manipulated and used to fix some brokenness in her life. When I had a conviction of conscience, she used biblical ideas to tell me that God could redeem what we were doing. She practically stalked me and my wife for months - but I let it happen. I have taken complete responsibility for the affair and do not fault or blame anyone but myself. I think that is why I’m struggling with whether this bitterness toward the affair partner is valid. Do I need to forgive the affair partner? How do I work on releasing unforgiveness and bitterness toward the affair partner while still accepting my responsibility for the affair? Is that a cop-out?