König?

You were Konig's best friend, he never seemed jealous when you got together with a recruit, but there was one in particular that if it made him angry, it was Ghost

One day like any other you were talking to Ghost but you didn't realize that König was watching them, a while later you went to Ghost's room and that made Konig's blood boil with anger

He went towards the door and hit it until he almost knocked it over and started screaming

Konig—"OPEN THAT FUCKING DOOR NOW!"