How's this sound:
The Simpsons take a vacation to this island, and it has pirates. And this long black haired pirate finds Lisa Simpson and tells her that she's the closest person to an adult that he's seen. Then they get into a relationship. Lisa books the flight arrangements back to springfield and that pirate says "I'm very proud of you Lisa" then they go back to springfield. It impresses him taking the responsibility of booking a flight. -The other women on the island just play around with the other pirates, drink and stuff and that does not interest this pirate.
The pirate gets in trouble because people of Springfield find out he's in a relationship with her, cause she's way under age. Lisa feels depressed and walks into the mud accidently, and complains "Ew. i feel so muddy now", not just the mud itself but getting him in trouble, then she begins to enjoy being muddy and start playing in the mud. -The pirate sees her and he goes and plays in the mud with her. Then he knows shes really a kid cause she's playing in the mud, and the people see that and they know they are just playing in the mud like kids.
By the way, I've dreampt this episode. Would this be a good part of a 'Simpsons' episode?