This is always a challenge and ultimately up to each individual to choose/practice forgiveness when they are ready and if they choose.
Forgiveness is the key to happiness is lesson 121 in the course and forgiveness offers everything I want -lesson 122.
From my perspective, it is not about “condoning “ negative behaviors. Decisions and boundaries can still exist even when one’s practicing forgiveness. I have only been able to “achieve “ this in partnership w the divine (for me the Holy Spirit)