I just want I add my support to those pointing out that your feelings here are incredibly valid. This is NOT just “what grandparents do” or at least if it “is” it’s not ok and it needs to change. I can relate. In my family there is an incredibly selective memory regarding the abusive environment we often experienced as children and a lot of what I’m doing with my therapist right now is being able to confront how that has imprinted on me. I’ve been gaslighted as to my bad childhood memories of so I can relate to the frustration you must be experiencing,

More than anything I would want closure on childhood or at least for a genuine ownership from the family members concerned for what they did. It’s totally right for you to want that too. I do recommend therapy as they may be able to help you focus your thoughts and support you should you decide to tackle this further with your dad. I wish you well.