The Marvelous Misadventures of Flapjack 1x5

The evil inventor's twin brother builds a "Grand Flying Contraption" to impress Bubbie, on whom he has a crush. However, when Bubbie does not return the same feelings (she sees him as a friend, rather than a love interest) he becomes very sad. Because of this, Flapjack and crew are inadvertently led into danger.