First of all, it has always been the case that parents have to sign if they fail the exam. If you fail the exam only once, I think your parents can only blame you at most. If you do this often, you should think about who you will give what you have learned in the future. If you want to do this for a long time, your parents have nothing to do with you. As a parent, I suggest you communicate well with your parents. They love you for your own good. So don't worry too much.