 In "Sid", he misinterprets Cassie's closeness with her gay Scottish friend and angrily accuses her of cheating on him, later destroying the laptop he used to communicate with her.In the same episode, a family visit proves too much for Mark to take and he dies, his body discovered by Sid the next morning.Still in shock, Sid goes to school as usual, but finally breaks down in front of Tony while at a concert.