What makes people think they can ask such things?

I've asked two questions on here about two relatives(one's a former relative), who have asked me to stay away from formal family functions, because they are embarrassed of me. But neither of them was hosting the formal event...but they felt they had to keep me away from the event to avoid embarrassment. My sister in law begged me not to attend my cousin's wedding which we're both invited to. It's NOT her wedding!!!!!!! My question is about the balls of these women....because I'd never even think of doing such a thing...I just wouldnt acknowlege the person if we were in the same room...I'd NEVER ask them not to attend something we were both INVITED to. Since the thought of doing this wouldnt occur to me, I was wondering how the thought would occur to some, n what would give them hope for a positive response. These women dont think they're byches, they think I'm one for not understanding politeness.