When there has been a violation of trust in a relationship, it is better for the one who has been violated to step aside and break fellowship with the person who was guilty of the violation. Of course, that person must be forgiven immediately.
The one violated needs to ask Me to help them not to become bitter or angry against the violator. Relationships are based on trust. Trust is earned, but forgiveness is granted freely.
Breaking fellowship with another believer does not mean that you will not pray for them. However, it would be difficult for the one violated to pray in agreement with the person who betrayed trust.
Pray that I will be able to speak the truth in love to the violator so that repentance (real change) can take place in that person's life.