Homer inscribe himself and Marge in a TV show in which two families swap mothers: Homer and the kids get a very strict woman, while Marge stays with that woman's husband, who develops a crush on Marge.
Lenny invites practically everyone in town to a party at his flat, where he tells them that he has a big surprise. He reveals that he bought a brand new plasma screen TV, and Homer immediately falls in love with its high-definition picture. He begins to spend all his time at Lenny's house, watching TV. Marge sends over the kids to bring him back, but they too get enthralled by the TV. Eventually three days later, Lenny tells him to Beat it!. When he gets back home, he just doesn't enjoy watching his usual TV anymore. Marge tells him that she entered them into a contest where the winner gets a prize that is a plasma screen TV. Later, they get a call, and they learn that they won third place as opposed to first ("Um... ..no. No one wins that."), and the prize is a trip to the Fox Studio Network (no expenses paid). While there, Homer learns of a reality show called "Mother Flippers" (similar to Wife Swap and Trading Spouses), and the grand prize just happens to be enough money to buy a new plasma screen TV. Marge agrees, although with reluctance, and they enter.
When they get back to Springfield, the show begins. Marge is traded to a nice, easy going man named Charles Heathbar and his perfect son, while Homer gets Charles' very strict wife, Verity. Charles seems to be the classic hen-pecked husband, and is surprised to see that Marge is extremely understanding and nice. Marge enjoys her time with Charles Heathbar, while he begins to develop a crush on her. Meanwhile, Homer, Bart, and Lisa are having troubles with Verity, who continues to discipline them and object to everything they do. She makes homework out of "Itchy and Scratchy" for Bart and asks Homer for his "synopsis" of CSI: Miami.
Back at Charles' house, he writes a love song for Marge (with guitar accompaniment), who seems completely oblivious to him until he comes out and tells her that he's in love with her. She explains to him that she loves Homer, and she tells him that he should tell his wife how he feels. He agrees, and decides to take her back to Homer and then get rid of Verity. When they get back to Springfield, Homer and the kids are ecstatic to see Marge. However, Verity has decided to leave him first, and she has already found a new partner: Patty. Apparently, they both hate Homer equally. Homer threatens to vote No on Proposition 38 (for Gay adoption), but a little arm-twisting by Patty makes him confess he wasn't planning to vote at all, a little more and he's in line.
In the end, Homer plays on the guitar, serenading his true love, his new Plasma TV (and Marge, too).