My mother posted an old picture of myself with 3 cousins and my sister who does not speak to me on FB. Well I make the joke that my sister was stuffing her face and her old poodle hairdo. We had always joked about that hairdo for years. So I saw no insult in it. It was one of those old perms that made your head look like a bowling ball. Well I just got a text from my other sister telling me I was rude on FB and I owed my other sister an apology. I just texted her back telling her I was not going to apologize since this other sister had called me liar and has accused me of other stuff. I just got done blocking them both from my page. Should I apologize or just continue with my life?