Following the wedding of his daughter Kay, Stanley T. Banks, a suburban lawyer, recalls the day, three months earlier, when he first learned of Kay's engagement to Buckley Dunstan: At the family dinner table, Kay's casual announcement that she is in love with Buckley and has accepted his proposal makes Stanley feel uneasy, but he soon comes to realize that his daughter has grown up and the wedding is inevitable. While Ellie, Kay's mother, immediately begins making preparations for the wedding, Stanley lies awake at night, fearing the worst for his daughter. Stanley's misgivings about the marriage eventually make Ellie anxious, and she insists that Kay introduce them to Buckley's parents. Kay calls the tradition "old-fashioned rigamarole," but arranges the meeting nevertheless. Before the introduction, Stanley has a private conversation with Buckley, and is pleased to learn that the young man is the head of a small company and that he is capable of providing a comfortable life for Kay. The Bankses' first meeting with Doris and Herbert, Buckley's parents, gets off to an awkward start, and goes from bad to worse when Stanley drinks too much and falls asleep in the wealthy Dunstans' living room. Following Kay and Buckley's engagement party, Stanley, who misses the entire party because he is in the kitchen mixing drinks, realizes that his plans for a small wedding have been swept aside and he will be expected to pay for an extravagant wedding "with all the trimmings." As costs for the June event spiral out of control, Stanley calculates that he can afford to accommodate no more than one hundred and fifty guests. The task of paring down the guest list proves too difficult, however, and Stanley reluctantly consents to a 250-person reception. The plans for a lavish wedding continue until the day that Buckley tells Kay that he wants to take her on a fishing trip in Nova Scotia for their honeymoon. Kay reacts to the announcement with shock and calls off the wedding, but she and Buckley soon reconcile, and the two families begin their wedding rehearsals. On the day of the wedding, chaos reigns at the Banks home as final preparations are made for the reception. The wedding ceremony brings both joy and sorrow to Stanley, as he realizes that his daughter is now a woman and no longer his child. The following day, Ellie and Stanley survey the mess in their home and concur that the entire affair was a great success.