Leave It to Beaver S06 E15 The Mustache

"Gee, Wally!"

Wally's on-again off-again girlfriend, Julie Foster seems to have thrown him over for a new guy in school who just happens to have a mustache. Wally's ego is bruised when Eddie tells him that Julie thinks he's naive and immature. This is the last straw and Wally decides to grow a mustache, much to the dismay of his family.