I wish the teenager who cheated my feelings a long life, no love and no children, and a long life. Is it appropriate to use this sentence in the QQ declaration of making friends? Will boys see it?
Not appropriate. You can't write such a vicious spell in the declaration of friendship. As long as you understand each other, communicate with each other and have the same language and hobbies, you may be congenial for a long time, otherwise it won't last long. Boys will not cherish you when they see this declaration, but will only think that you are not a kind and gentle girl and can make bosom friends. Writing such a declaration will have the opposite effect.