Thanks for the update! I'm glad that you didn't act on the assumption that your father was correct that you were invited. I'm glad that he's found another ride so that he won't hound you.
And because I can't help myself because your father sounds so much like my mother and my uncle, I have to just say the following three words: Narcissistic Personality Disorder. It explains why people like him so much that he's fun and interesting to be around. It also explains why he has zero appreciation for all the time and effort you and your cousin are often willing to put in to help him.