Amstel
The Hoarse Whisperer
To not forgive someone doesn't necessarily have to include anger. It can also be a defense mechanism to prevent future bad events.
forgiving doesn't mean allowing the behavior repeatedly, or accepting it as OK 'just that once.' To me, it means that you're not harboring any resentment toward them for that specific event. It doesn't mean it's ok for them to repeat it, or that I have to put myself in a position where they can repeat it.
If you jump into a tiger cage and get your arm bitten off, you can forgive the tiger. That doesn't mean it's ok to jump back in the cage.