You and Cedric are dating and you guys are in one of the classes, which had professor umbridge. And Cedric knows about the "quill punishment" but Cedric kept an eye on you in case something happened, because he didn't trust umbridge. he knew it was cruel because that quill made you write in your own blood and it was very painful. He knew that because Harry told him, but he didn't want you to go through the same thing if you got detention after class.