The Osbournes struggle to come up with a gift for Jack's birthday. Kelly strongly objects when Jack dances with Christina Aguilera, whom Kelly had previously insulted on a number of occasions. Kelly complains that Jack is disrespecting her by hanging around someone that she dislikes, and insists that she would never do this to Jack. Jack tries to explain that Christina actually had nice things to say about Kelly. The kids get into a brawl, which Sharon must break up. Meanwhile, Ozzy visits the dentist and intakes a bit too much nitrous oxide. The family visits a medieval-themed club to celebrate Jack's birthday, and buys him a knight suit. Jack tries out his new sword by dueling with a buddy in the street.