S1·E129 Star of Tomeow-Meow

Heathcliff and Sonja land the leading roles in a movie which is filming in her town. However, once on the set, Heathcliff discovers he is merely a stunt double for a temperamental star. After surviving several rigorous stunts, Heathcliff challenges the conceited star, who storms off the picture, leaving Heathcliff to do the final love scene with Sonja.