Am I wrong? Racist father

My sister who I am very close with is having a gender reveal this weekend. My father will be there and I do not speak to him at all because he chose to call my son and my husband the N-word. My son was only five weeks old when my father called my son this. My son is now 13 months. My father is a racist man I haven’t spoke to him in a long time. I completely disowned him. I completely forgotten about him. It’s like I never even had a father. I don’t even think of him. My husband is a great man. I always say he’s the type of husband you see in love movies. It was a whole situation with my father and us. My father called the police and told them that my husband punched him in the face which was a complete lie and he got in trouble for making a false police report. We moved away. And we only really see my sister and my grandma now. I told my sister I do not want to go to the gender reveal because my father is going to be there and I would have no choice but to bring my son. And she’s mad at me. Am I wrong