DEAR ABBY: My nephew is 19. I have been co-parenting him and his sister since they were 15. He has some issues that are normal for his generation. What isn’t normal is his inflated sense that life is all about him. If it doesn’t benefit him, he doesn’t do it. I have been giving him the structure, guidance and direction that he has asked for, but he’s not changing. His girlfriend has been on him about his poor hygiene, but he doesn’t change.