After winning a bet with Homer on the Dewey/Truman presidential election of 1948, Lisa gets to pick the day's father/daughter activity. She chooses to help build houses for the homeless. After getting paint on his wedding ring, Homer takes it off. Two business women see Homer's bare finger and take to him. Driving past the scene, Marge sees what she thinks is Homer flirting with the women. In fact, he's explaining in detail how Marge gave birth to Bart.
Marge begins to worry that Homer isn't as attracted to her. Manjula advises plastic surgery, and Marge goes under the knife for some liposuction. Waking up, she finds that the doctor accidentally gave her breast implants instead.
At first, Marge enjoys the attention and her new trade show modeling career. But she eventually tires of the leering and back spasms and gets the breasts removed.