Members Only is an episode of the ALVINNN!!! and The Chipmunks series.
While Alvin voices his complains about the latest math test he just got back, the Mathletes hold a meeting until they are interrupted by Derek's bullying. Despite Simon urging them to stand together, they hide and leave Simon behind to face Derek alone. Alvin witnesses the incident and advises them to get into Derek's grill instead of backing down. They are confused but come to a consensus that Alvin should teach them to stand up to Derek; in return they will do his homework (Simon disagrees). Alvin gives them each a nickname and teaches them to look tough. After Alvin gets a perfect score on another math test, much to the disbelief of Miss Smith, he watches the Mathtrons (their new group name) be jerks to Derek by teasing him with math questions. Though he's proud of their progress, he's also confident he can refine their behavior. At lunch, Alvin tries to get their help at preparing him for his next math test, but they refuse, happy with their new status. Simon, fed up with their bully image, resigns from the Mathletes. In order to stop the new group of bullies, Alvin comes up with the idea of getting their mothers involved. They express their disappointment in them using their brains to bully others. Now that the Mathtrons are taken care of, Simon agrees to give Alvin a math crash course for his test.
- "We Are The Show" 
- Ms. Whisker's makes an appearance, her first since Good Luck Mr. Whiskers.
- This episode reveals that Cheesy is ambidextrous.
- When this episode premiered in the US, it aired with a rerun of My Sister The Weirdo.
- Theodore does appear in this episode, but has no lines, making Alvin and Simon the only characters to appear so far in every episode and having at least one line.