Homer gets into trouble over his football gambling debts and allows the Springfield Mafia to shoot a porno film in the house; Marge leaves for the beach—and encounters a marine biologist named Caleb (voiced by Alec Baldwin) who has dedicated his life to saving manatees.

!! Tropes:

* ArtisticLicenseBiology: Caleb implies manatees and dugongs are the same animal, when they aren't.
* ICanChangeMyBeloved: Deconstructed. Marge is fed up with Homer acting the same way he always does. However Caleb points out that Homer isn't at fault. He's still the same man she fell in love with. The problem is that she still expects him to change.
* {{Irony}}: The Santa village where Homer sends his family to so they won't know he's allowing the local mafia to make a porn movie at their home doesn't open during Christmas.
* PickOnSomeoneYourOwnSize: Homer says this to the guys who are hassling the manatees. They point out that the manatees are at least their size if not larger.
* SeldomSeenSpecies: Manatees are a major plot point in this episode.
* TooDumbToLive: After Homer convinces some bullies on jet skis to leave the manatees alone, Homer insults them.