"Marge and Homer Turn a Couple Play" is the twenty-second episode of Season 17, and the season finale.
The Springfield Isotopes's star first baseman is having marital problems, so when he sees Homer and Marge kissing on the Jumbotron, he asks them for advice, but when Homer is later caught giving a neck massage to the player's wife, they break up again - and it's hard for them to give advice when they are not talking to each other themselves.
The show opens to the family watching a cop drama. As the credits roll, Kent Brockman announces that the Springfield Isotopes are in first place thanks to their new acquisition of Buck “Home Run King” Mitchell. “To the bandwagon!” shouts Homer, as they all head to Springfield Stadium. Buck’s pop star wife Tabitha Vixx, a parody of Britney Spears, sings the first few bars of the American national anthem at the game, then strips down to lingerie and launches into one of her own songs, which shocks the audience (especially Bart). After a minute of lascivious dancing, she concludes, “...and the home of the brave.” Buck, humiliated, delivers a terrible performance at that night’s game, even accidentally letting go of the bat while swinging it which accidentally hits Sideshow Mel’s fiancée, causing the crowd to boo at him. He later sees Homer and Marge kissing on the JumboTron; later that night, Buck shows up at the Simpsons’ front door and asks for help with his marriage in exchange for season tickets.
Marge doubts their ability to counsel another couple. Her doubts lead to her and Homer flirting, which Buck sees and claims is an example of what he wants with his own wife. At the first session—taking place in the Simpsons’ living room—Buck confesses he assumed Tabitha would give up her recording career to focus on his minor league baseball career, to which she responds she won’t stay in a mismatched marriage. The session concludes with Homer asking Buck to sign dozens of baseballs (as a present for Bart), which pour virtually endlessly from the bag. At school the next day, Bart and Lisa dicuss about how weird it is that their parents are giving marital advice, as they always argue about everything. In the background, Homer is heard yelling, "And I say a monkey can mow our lawn!"
The next session takes place at Buck and Tabitha’s mansion and goes much more smoothly. As a result of his now-steady personal life, Buck's game returns to superior form and the crowd loves him again. Tabitha continues her singing tour, and the Simpsons attend one of her concerts. When Tabitha begins pole dancing in lingerie again, Bart says, "I have a sudden urge to give her a five-dollar bill," prompting Marge to walk him and Lisa out of Tabitha's concet. Homer comes to meet Tabitha in her dressing room to check up on matters. He observes a bucket of fried chicken and says, "Oh, you're so hot! If only I've seen you before I meet my wife!" Tabitha is at first flattered, but then realizes that he is talking to the chicken. She asks Homer to give her a neck rub; her loud moans and Homer's praise of the fried chicken he is eating are overheard through the door by Buck, who misinterprets them and barges in and then slugs Homer.
Now with his marriage again on the rocks, Buck goes into another slump. Homer wants to get them back together, but Marge refuses to help. He leaves, and a few minutes later Tabitha knocks on the door; she tells a shocked Marge that she plans to leave Buck for good. Marge objects, insisting they stay together. Tabitha then remembers that Buck was the first man that didn't just like her for her body, as he always complimented her on her hair. She then notices that Marge's standing lamp is dirty and begins pole dancing to clean it. Bart comes downstairs while talking on the phone and says to the other person, "Cancel all my appointments." Marge leads Tabitha out the door.
Buck Mitchell is next seen at the plate in the bottom of the ninth. Homer has hijacked the Duff Blimp and spells out a message to Buck, supposedly from Tabitha proclaiming her love. Buck, reinvigorated, hits the ball into the blimp itself, causing it to crash into the field; as Homer runs from the wreckage, Buck realizes Tabitha had no part in the message. He charges Homer, bat in hand, but Marge delivers a monologue over the Jumbo-Vision, dissuading him. Tabitha then comes on the Jumbo-Vision to tell Buck she wants to stay together.
The episode finishes with another Isotope player, Tito, saying he doesn’t care about the healed marriage because bandits just kidnapped his mother.