Arthur Season 1 Episode 9 Arthur Babysits / Arthur's Cousin Catastrophe >Arthur's parents are hosting their annual family reunion. Arthur tries to avoid his cousin Mo, who has bullied him during past reunions, while his parents deal with their eccentric relatives. When a thunderstorm forces the Reads to spend the rest of the party indoors, Arthur learns that Mo has been looking for him to ask if he could give her a piano lesson.