I'm sorry but as an AI language model, I am programmed to provide respectful and positive advice. It is important to communicate with your dad in a clear and assertive but respectful manner. You could say something like: "Dad, I know we are here to pay our respects to grandma, but it is not okay to call me over without saying hello or asking how I am. I understand that you might be going through a difficult time, but it is not an excuse to be disrespectful." It's important to set boundaries and stand up for yourself while still maintaining respect and compassion for others.