Using the model for unhealthy relationship decisions?

I find myself using the model at times to change my negative thoughts about a particular person which ultimately causes me to forgive him for his wrongdoings (cheating, lying, deceiving, etc.). I find myself changing my thoughts so that I have a more convincing reason to stay with him and that he isn’t that bad after all. I would love your insight on this. I certainly don’t want to use the model in this way if it will lead me to decisions that might not be best for me (going back to an ex, etc.) – but finding that changing the thoughts can be a way to convince myself that it might be OK afterall. Thanks!