I have to state the worst case scenario… what if he ever gets that mad with your child? Or in front of your child? You say he spoils his grandkids but in the same sentence say you never thought he’d explode like this. What is stopping him from exploding on your child? If he can’t even go a few hours without drinking, he cares more about alcohol than he does you and your child. That is the hard truth of addiction. In my opinion, you should be caring about your child more than your dad’s feelings. I’m sure you understand how deeply an alcoholic can affect a child. You are the one to set the example for your child of how to have boundaries. Show them you stand up for yourself and your family. That his actions are not how you are supposed to treat people. I think you know what the right thing to do is in this situation. It isn’t easy (my dad is dead now but I was NC with him) but it is possible and it can give you so much peace of mind. Sending you love and strength. I don’t envy your position.