My sister and I have never been close, and things have escalated to the point that she is accusing me of things I never did and telling my father how low her opinion is of me. Recently I overheard her telling my nephew that I'm a "filthy f***g whore piece of s**t" Why? I have no idea...
She found out I overheard when I sent her a message, explaining that I was removing myself from her life, and even then she thought she was invited to the wedding. It was only after discussing it with my nephew that she realized, and she's mad at HIM, presumably because it was his fault I know how she feels.
She believes she is entitled to an invitation because she is a blood relative, especially since there will be people at the wedding whom she also hates.