Plot summary

Following the events of the first film, Ben Healy and his adopted son Junior decide to leave Cold River for a new life in Mortville, which is known as ''the divorcee capital of the world" as Ben is greeted by an endless number of single women when they arrive at their new house, as well as hotshot single dad Aron Burger, who invites Ben and Junior over for a housewarming barbecue. After being insulted by Burger and and his bratty twin daughters, Dolly and Madison, Junior seeks revenge by turning up the barbecue's gas pumps, causing Burger to get blown in the air and landing in a kiddie pool in the next yard. The next day, Junior begins his new school year at Mortville Elementary, where he runs into his old nemesis, Mr. Peabody, now the school's principal,. When Junior purposely breaks wind in front of Peabody, he foolishly tricks Junior into thinking he is a smart kid and passes him to the sixth grade. Of course, Mr. Thorn, his homeroom teacher, is not happy that he is saddled with many of his old students again, as hardly any of them passed last year, including the hulking Murph, who has been held back for twenty years. When Junior steals a math question answer intended for Murph, Thorn is somewhat impressed with Junior's attention and leaves the room to find something that will help Murph pay more attention. Then, a chase then breaks out all over the classroom between Junior and an angry Murph, ending with Junior taping him up on the blackboard, causing all the terrified teachers and students to run out of the school.Meanwhile, Ben visits the local bank to get a loan approved. The bank's owner and wealthy heiress LaWanda DuMore, observes Ben from her office window and orders her assistant, Smith, to find out everything he can so she can woo Ben. Later, when he picks up Junior from school, Murph gets up on the roof and pushes a decorative satellite dish off, intending to hit Junior, but accidentally crashes on top of Ben, knocking him unconscious. When he wakes up, he finds himself greeted and tended by Annie Young, the school's nurse. Of course, her daughter Trixie, who remembers Junior's face as he shot her balloon with a slingshot the day they moved in, notices him attempting to deface a school portrait of Annie with a black marker and clobbers him. The next night, Ben goes out on a date with Debbie, one of the neighborhood's many single women, and leaves an unhappy Junior with babysitter Rhoda. To get rid of her, Junior calls Debbie's jealous ex-husband, Voytek and tells him they are on a date. He shows up at the restaurant, where Ben and Debbie are dining, and smacks Ben on the head with a lead pipe, but when he tries to defend himself, Debbie, who still has feelings for Voytek, knocks Ben to the floor. Back home, Rhoda's boyfriend shows up and they go to Ben's bedroom to have sex. After returning home humiliated, Ben sees several cars parked at and around the house and sees everybody in his front yard watching Rhoda and her boyfriend having sex projected from a video camera on the exterior. Shortly after, Big Ben arrives, claiming to be on vacation, but admits he is on the run from his creditors as he lost his business and all of his money. Ben and Junior reluctantly allow him and his pet dog, Nippy, to stay at the house.The next day, after Junior is sprayed with the fire hose by Trixie, Ben arrives to pick him up in the nurse's office and it is becoming quite clear to Junior that Ben has feelings for Annie. However, Ben announces to Junior that he has another date with Emily, another single woman. While Ben gets showered and dressed, Junior rigs the doorbell with electrical wires, electrocuting Emily. Ben, feeling distraught that he is not giving Junior giving enough attention because of his dating game, decides to spend more time with him. One day, He takes Junior to a water park, a ball game, and finally to a carnival, where is unable to ride the Crazy Dance, a popular ride, because of his height, and after getting snubbed by Murph and Trixie, who secretly uses stilts on her shoes to gain access, Junior gets revenge by expanding the ride's speed, causing everybody in and out of the ride to vomit every which way, as well as on each other. Though frustrated, Ben makes a deal with Junior that he will be there for him, providing he will be good. When they get home, they discover the house has been entirely redecorated by LaWanda, who also secretly threatens violence to Junior if he tries to come between her and Ben. After discovering his new bedroom has been become a haven for clowns and themed toys, Junior sabotages a home-cooked meal by LaWanda by putting roaches inside a salad and spawning through the rest of the dinner. An angry and betrayed Ben scolds Junior, deeming him untrustworthy, and an equally angry LaWanda tells Junior that she plans to marry Ben and then send him to a Baghdad boarding school.During Junior's school's open house, Ben gets a dose of what Annie's daughter is really like when she hijacks a puppet show and an embarrassed Annie drags Trixie out of the school. Ben runs after them, explaining that he can help Annie, but she bitterly confesses she has no room for anything else in life and and they disappear into the night. Since Ben still has feelings for LaWanda, he accepts her subsequent marriage proposal, much to Junior's dismay. He gets revenge by switching her mandatory blood test with a rabid dog's and sent to the hospital, where Junior also switches LaWanda's hospital file with another patient's paperwork for plastic surgery of the nose. That night, Ben and Junior run into Annie and Trixie having dinner at a pizza place. with Peabody and his girlfriend in attendance and after berating all of them, they get into a food fight, causing Ben, Junior, Annie, and Trixie to be kicked out and permanently banned from the restaurant, but Junior and Trixie now become friends and must band together to stop LaWanda from marrying Ben. Later that night, Trixie shows up at the house and she and Junior plan to go to the local park monument, the Love Rock, and they bound and gag Big Ben, fearing he will tell.Early the next morning, Ben receives a phone call from an alarmed Annie and they drive to the park, where they see Junior and Trixie sleeping on a bench and after embracing, the two couples go their separate ways. At the backyard of LaWanda's mansion, where the wedding is being held, Junior hopes that Ben will see LaWanda's nose. However, the plan backfires when Junior discovers she got last-minute surgery done on it. They go ahead with the ceremony until it is interrupted by Trixie driving a bulldozer into the yard, containing the Love Rock. It rolls down the aisle as guests scramble out of the way. LaWanda firmly stands her ground and puts out a hand to stop it, crushing her into the ground. Annie, upset that she is too late, arrives and scolds Trixie, but Ben declares the wedding was meant to be ruined. Since Ben and Annie now have feelings for each other, the two passionately kiss. After Big Ben attempts to persuade Ben to marry LaWanda, he suggests his father should, much to his joy. He goes over to help Smith free LaWanda and she and Big Ben kiss. To celebrate, Junior slingshots a stick of dynamite into the wedding cake, rocketing it in the air and plasters all over Big Ben and LaWanda.