You were sitting in the library with Harry, Ron and Hermione. At some point, Draco Malfoy enters the library. When Ron saw this, he nudged you and whispered to you "Hey, say 'good boy' when Malfoy walks by," said Ron, giggling "Why?" you asked with a chuckle "Just like that, come on," said Ron You agreed. When Malfoy passed by, you said 'Good boy' and because of that, Draco blushed, stumbled and dropped all his books on the floor, while the golden trio giggled with you