"Co-Dependent's Day" is the fifteenth episode of Season 15.
After a trip to a vineyard, Homer and Marge plan to go on a drinking binge together. But, when Homer crashes the car while drunk driving, he frames a passed out Marge as the driver to avoid being arrested (this would have been his third strike). Marge takes the supposed crime seriously and makes a considerable effort to rehabilitate herself.
Homer, Bart, and Lisa see the newest Cosmic Wars film, The Gathering Shadow, and the movie turns out to be less than what they expected, filled with boring senate meetings and racial stereotyping. At home, Marge suggests that Bart and Lisa should write a letter to Cosmic Wars creator Randall Curtis. Two weeks later, they get a reply from Curtis, which completely ignores their criticism, having sent them Jim-Jam Bonks merchandise.
This forces the Simpsons to go on a trip to California, where Homer and Marge go to wineries, while Bart and Lisa go to the Cosmic Wars Ranch, which was previously known as Fresno. Bart and Lisa meet Randall Curtis and tell him that his Cosmic Wars movies have lost their way. He, however, does not like what they are saying, especially when Lisa points out that better technology is no way to make the story better. So, the two encourage him to return to what inspired him for the first Cosmic Wars movie. Curtis agrees, and he decides to go back to his storytelling roots. (For inspiration, he plans to go to the video store, and rides there on a tauntaun)
Bart and Lisa rejoin Homer and Marge, who are both drunk from free samples of the wine (while tossing Randall Curtis around like a football). Back in Springfield, Homer and Marge go to Moe's Tavern and drink more wine. Moe opens a priceless bottle of Chateau Latour wine from 1886, clearly unaware of its value. But, when he checks a wine guide like he should have done beforehand, he breaks down crying and dries his eyes with a lost Shakespeare play.
Eventually, Homer and Marge then continue to drink heavily for several days, until Marge suffers a particularly painful hangover. She tells Homer that they should not be drinking, and he agrees. Unfortunately, when they go to an Oktoberfest featuring Grammy-winning nuclear polka band Brave Combo, Marge, who tries to go through the night without drinking, gives in and ends up drunk (again), along with Homer. He tries to drive them home, but, in a drunken stupor, overturns the car.
In order to avoid an arrest, Homer makes things look like that Marge (who is much more drunk than him) was the driver. The police arrive and she is arrested, but Homer bails her out. Later, Barney suggests that Marge should go to a rehab clinic for a month, and while Marge is gone, Homer lets Flanders take care of the kids. When he sees her at the clinic, he confesses, but Marge is relatively furious with Homer for getting her arrested and drinking again. Eventually, the other rehab patients at the clinic help her discover that she likes being with Homer more than drinking, so she forgives him and returns home with him.
Behind the Laughter
The scene where Homer sings at Moe's Tavern while Marge plays the piano was a deleted scene of this episode. However, it was later used in "Mommie Beerest" as a postscript scene during the end credits.