Homer, Bart and Lisa go to the carnival on the South-Side Sea Port, and Homer indulges in various varieties of kabobs. While devouring them indiscriminately, he accidentally swallows a flaming stick. He tries to douse it out with water, but gets tricked by Bart into drinking lighter fluid (prompting Homer to strangle and breathe fire at him). Following a brief stint in a tongue cast, Homer's taste buds become hypersensitive, making eating ordinary food an ordeal. Lisa remedies the problem by giving Homer cafeteria food from Springfield Elementary, which is so bland that a supertaster like Homer can tolerate it. Homer decides to dine at the elementary school (and even goes so far as to be a cafeteria server), much to the embarrassment of Bart.
While dining at the school, Homer meets a "helicopter mom", who pressures her son Noah into succeeding by being near him at all times. She makes snide remarks about Homer's children, pointing out how dumb Bart is and how much of a social outcast Lisa is. Homer decides to become a "helicopter parent", fearing that his children's only ambition in life will be to serve children like Noah. Bart must build a balsa wood model to compete in a sculpture assignment, and Homer insists on helping. While shopping for balsa wood, Homer reveals that Bart will build the Washington Monument, but Principal Skinner criticizes this as overly easy. In response, Homer purchases a model kit of Westminster Abbey. He buys a book for Lisa entitled "Chicks with Cliques", and persuades her to try joining a clique, first by declaring that dolphins swim in "cliques" and that the United States was founded by a clique, and then by hosting a cellphone-decorating party for the popular girls.
Homer is convinced that Bart will not build the Abbey model correctly and insists on building it himself. He works late into the night and accidentally falls asleep. During a dream sequence, ghosts of some of the historical figures Homer imagines are buried in Westminster Abbey — including Oscar Wilde, who is actually buried in Paris — advise Homer to let Bart learn from his mistakes. Homer awakes to find he has accidentally crushed the model beyond recognition. At the competition, Superintendent Chalmers notes that Bart's model is the only one that does not appear "too perfect", and thus believes that Bart's model is the only one that was not constructed with the help of a parent, but Bart declines the award and reveals that Homer did all the work. Lisa too confesses to her father that she no longer wants to be popular, noting that "it's hard work being this shallow".
Meanwhile, Marge changes the water heater in the basement and discovers a hidden sauna, keeping it to herself out of fear that Homer will invite his friends and Moe (the latter of whom - in a scene Marge imagines - does not bring a towel as he believed they would "go Scandinavian"). Marge visits the sauna on a regular basis and is so deeply relaxed that she does not react when Homer tells her of Bart and Lisa's problems. After Bart declines the balsa model award and Lisa leaves her clique, Homer believes he has failed as a parent. Marge leads him downstairs to the sauna where they revel in steam and relaxation. In the end, Marge douses the sauna rocks with beer and as their towels fall off the two kiss.