I'm going to refuse to go to my nephew's birthday party
Why ignore your nephew's birthday?
I'm angry at my sister because I think she has insulted me at a party.
Don't make your nephew suffer for your sister's actions. Family should support each other no matter what.
I still don't want to go.
You really should reconsider, you're expected to go to family events and I'm sure your nephew would love to see you.