Marge buys a tandem bicycle because she thinks Homer will ride with her, but when she ends up trying to ride it on her own (and failing miserably), Bart decides to ride with her. When the teahouse they go to (Marge for the tea, Bart for the cakes) closes, Bart turns his treehouse into a teahouse, but when others call him a mama's boy, he suddenly turns on Marge. Meanwhile, Homer buys a dumbbell from a strongman and, after lifting a pinball machine with one arm, Moe gets Homer involved in competitive arm wrestling.
The Simpsons make their way to Paradise Pier, a Coney Island-like place with old carnival rides. They're shocked to realize that the pier is being torn down. Homer jumps on a bumper car and rides off, eventually landing on an electric trolley track and colliding with Wiggum's police car. Later Homer takes an interest in a dumbbell that's for sale, and Marge buys a tandem bike after Homer says he'll go riding with her. At home Homer absentmindedly pumps his dumbbell day and night. When Marge asks him to go riding with her, Homer shows no interest. Neither does anyone else in the family. When Nelson notices Marge riding the bike all by herself, he concludes that she's lonely. Bart insists that "moms don’t get lonely," but he can’t help but feel sorry for Marge. He climbs onto the bike and asks Marge if she’d like to go for a ride. Marge is elated.
Marge and Bart ride the tandem bike to Springshire, which is reminiscent of the English countryside. They find a teahouse and decide to check it out. Inside, Marge sips tea as Bart wolfs down cakes. Bart gets an English gentlemen to recite a spell from the Harry Potter books, causing Bart to float in mid-air. Homer enters Moe's bar, where he discovers Moe and some of the barflies trapped beneath a pinball machine. He easily lifts the machine using his strong right arm. This gives Moe an idea. When the Rich Texan man enters the bar, Homer pretends to be a nerd, and shows off his wimpy left arm. Moe tells the Rich Texan he’ll bet a hundred dollars that Homer can beat him in an arm wrestling fight. When the Rich Texan realizes he’s been conned, he demands several favors, including a walk on the beach. Bart and Marge ride back to the English-style village, only to realize that the teahouse went out of business. As Marge and Bart pedal back to Springfield, Marge remarks that she and Bart will have to go back to doing their separate things. Feeling sorry for his mother, Bart invites Marge to spend some time with him at his treehouse. Marge enters the treehouse and begins tidying things up, turning it from "treehouse to teahouse." Homer tells Marge that he’s decided to join the professional arm-wrestling circuit. Bart and Marge make their way to the Springfield mall, where Bart buys a Krusty the Clown tea service. Jimbo, Dolph, and Kearney spots Bart with the tea service and begin making fun of him. They call Bart a "momma's boy." Bart smashes the tea service and tells Marge that he’s only been hanging out with her because he felt sorry for her. Marge is devastated.
Lisa tells Bart that she's worried about Marge, who has been petting Santa's Little Helper for hours. Lisa says that Bart broke their mother’s heart. Bart finds Marge sitting at the kitchen table, sadly stirring some tea. Bart tells Marge that he enjoyed hanging out with her, and suggests they team up for karaoke night at school. Homer laments that Marge hasn't called him. Moe makes up a story, assuring Homer that Marge did phone, and said that she loves him... and that he should break his opponent's arm. As Homer arm-wrestles his opponent he calls home, and loses all interest in the sport when Marge doesn't answer. Homer runs off, leaving Moe behind. On karaoke night Marge grows increasingly worried about Bart, especially after they get dressed up in identical outfits. When Marge sees Principal Skinner and his mother singing a song, she envisions an emasculated, middle-aged Bart ending up the same way. Horrified, she tells Bart she's not going to let him turn into a momma's boy like Skinner. She hands him a fire extinguisher, and encourages him to return to his former mischievous self. As Marge giggles, Bart turns the fire extinguisher on the crowd and begins blasting away.