Homer, Bart and Lisa are waiting in line at the DMV to get Homer's drivers license renewed. Bart observes Noiseland Arcade across the street, which prompts Homer to leave Bart and Lisa in the line and go there himself. Bart gets offended at Homer, because he went to a birthday party he was invited to. When Homer returns, Bart and Lisa give their spot in line to Fat Tony, as Homer left Bart and Lisa standing in line at the DMV, wasting their last day of summer vacation. After Selma refuses to process Fat Tony's form and save his place in line, she gets bagged by Fat Tony's goons while going outside to smoke. The hoods place her in the trunk of their car, and the pair tell each other that Selma weighs more than a safe filled with cash that is also in the back.
In the forest, Bart and Lisa each get each other's germs on themselves, and after an hour, Bart sniffs out truffles which are growing in the roots. Lisa is surprised at this, and gives the truffles to Luigi, who is also out looking for truffles with Plopper. Luigi makes a deal with Bart that if he can find more truffles, he will be given "top dollar" for them and given the best table at the restaurant.
At an abandoned warehouse near the waterfront, Fat Tony's mob unbags a tied up Selma, and Fat Tony asks her what part of her body she wants to be cut off first. Selma demands that she has liposuction. After a few choice words, Fat Tony agrees with Selma. Then Selma shows off her new look and Tony tells his mob to leave with the doctor, as he wants some private time with Selma.
At 742 Evergreen Terrace, Marge can't keep looking at Selma, and when Homer comes in badmouthing her, Fat Tony arrives. Homer starts stuttering and explains that he was complimenting her. Tony knew what was going on and forgives Homer if he draws a portrait of Patty. Homer's drawings turn out bad, and he can't keep helping himself to draw her as a monster. On their date, Fat Tony proposes to Selma, while his other mobster drown a member, and sings a song which makes agents in the FBI van put Selma on the mob hierarchy.
In the woods, Lisa forces Bart to search for more truffles, as big as the head of Cletus' new baby.
At the wedding ceremony, Marge get displeased at Selma for putting her at the table with the low-life, and the two fall out during the photo-taking. Fat Tony saw what Selma and Marge are going through, and invites Homer and Marge to stay with the couple at his new mansion on the Jersey Shore.
Back in the woods, Lisa is getting tired with Bart and argues that his scent of smell for truffles is failing. As Bart tries to storm off, he trips and knocks his head against a tree, knocking himself out. When Bart wakes up, he is treated like a dog from Lisa and forced to look for truffles. Bart gets a scent, which leads to a closet in Lisa's bedroom. Lisa explains that she ate the truffles because vegetarian food is so boring and bland. She tells Bart to give it to someone who deserves it, and Bart chooses Plopper. Unfortunately, Bart realizes that he has made the wrong choice when Plopper then goes haywire, eating anything that includes truffles throughout the restaurant.
Arriving at Fat Tony's mansion, Marge doesn't think it is a good idea to stay with him and Selma, but Homer does. Fat Tony introduces his nephews and niece to the couple, and when Marge stumbles into Selma, all made-over, they have another falling out. While Homer is forced to chug a whole keg of beer, Selma tells Marge about the growing relationship between Fat Tony and Homer. Selma, Marge, Homer and Fat Tony "start over" by enjoying themselves in a hot tub. Afterwards, Homer and Marge are trying to find their room, when they hear Fat Tony talk to his fellow mobsters and the two realize Tony has a "goomar" (mistress). Marge and Homer tell Selma, and Marge immediately wants to leave. Homer doesn't want to, but Marge forces him to. After offering Homer several pool noodles, Fat Tony gets an unwelcome visit from Selma, who is outraged with the kingpin for having another woman. Suddenly, Fat Tony's actual wife walks in, or in fact crashes through the fence in a car at high speeds. The furious woman then exclaims that this "other woman" is the goomar, although Selma seems to differ. Tony explains that if Selma was Italian to which is not, she would know about the "goomar" business. His actual wife then shouts that Fat Tony missed her open house because of Selma, and Selma gets into a fight with her. Homer and Marge get out of the way, and put themselves in the tanning bed.