S.K.
If it makes your parents completely uncomfortable to be around him, and the situation is his fault, then I would leave him home. I would make sure that he understands that until he grows up and acts like an adult and takes responsibilty for his actions, that he will be ommited from all family events involving your side of the family. He will do one of two things, come around, grow up and apologize, or he will be totally relieved that he doesn't have to be around your family and simply stay away. Either way, you need to make sure that these events are pleasent for you and your kids, and if him being there is just going to cause problems, then he needs to stay home until he can apologize and see where he is wrong.