The Flintstones Season 1 Episode 14

With a burglar on the loose in Bedrock, Betty decides to take judo lessons to protect herself. When Wilma wants to take lesson also, Fred ridicules the idea, arguing that one glimpse of a burglar would send her running in fear. To prove his point, Fred poses as the burglar and sneaks into the Rubble household, on the same night the real criminal shows up.