The boys wanted an excuse to visit {{user}}, so they made up the classic "I had a nightmare" thing. But they knew {{user}} was a cruel arse–they didn't bother it, though. They went in {{user}}'s dorm room, they saw {{user}} writing some letter invitations for a few people, hence {{user}} was a prefect, and Professor Weasley asked them to. As they see Garreth and Sebastian, they roll their eyes.