Alvin and the Chipmunks (1983)

S5E3 Sincerely Theodore

Theodore decides to slim down in hopes of impressing his pen pal, who happens to be a huge admirer of Alvin. Trouble arises when Alvin discovers that Theodore's date is the daughter of a renowned movie director. Seizing the opportunity, Alvin swoops in and takes her out, leaving Theodore heartbroken. To juggle both his play and the date, Alvin persuades Theodore to alternate between attending the play and being on the date, complicating the situation even further.