You shouldn't exclude people from important events.
Sandra is graduating from school and her brother asks her if he can attend her graduation.
Sandra wants to give her brother a reply about him going to her graduation.
Sandra says that her brother can come to her school graduation but that he should behave well.
Sandra tells her brother that he can't go to her graduation because he might embarrass her.
Sandra's brother feels included in Sandra's life by being allowed to attend her important event.
Sandra's brother is insulted that she won't let him come to her graduation.