The McBrides are holding a cat-themed party for Cleopawtra and Nepurrtiti, as they have recently graduated from Madame Furball's Academy for Refined Felines. As the celebrations continue, Harold gets a call from Gayle, who informs him that it's her birthday today, and is looking forward to the party he has planned for her. After they hang up, the McBrides realize in their horror that they spent so much time planning for the cats' party, that they forgot about Gayle's birthday. Wanting to keep a promise to his mother, Harold tells Clyde and Howard that they will get the items necessary for the party. Before they head out, Harold instructs Cleopawtra and Nepurrtiti to take control of the party.
Unfortunately for the McBrides, everything that they want for the party is taken at the last second, like Lola taking the last red velvet cake for a sweet 16 party for Eunice (Harold does gets it from her by trading away his watch, only to ruin it by running into a sign), Cheryl and Meryl buying every single party decoration for a watch party (Howard tries to get a plastic tiara they dropped, but is threatened by a father who wants it for his daughter), and Clyde is unable to book Luan for entertainment due to having already been booked by Lola for Eunice's sweet 16. As the McBrides arrive home, ready to head to Sunset Canyon to break the news, they realize that they can use the decorations for Cleopawtra and Nepurrtiti's party for Gayle's party.
After grabbing as many decorations as they can, the McBrides arrive to Sunset Canyon and quickly set up the decorations. Upon setting everything up, the guests (Scoots, Tyler, Seymour, Bernie) arrive, including Gayle. However, since everything about the party is cat-related, like the decorations, party favors and gifts, the McBrides are forced to create fake excuses so that Gayle doesn't get skeptical. Sometime later, after numerous lies from the McBrides, it's time to break the pinata. However, the pinata is filled with catnip instead of candy, and within seconds, a clowder of cats arrive and begin attacking the guests; it turns out Scoots had been hiding numerous cats in her room, breaking Sunset Canyon's rule of residents having only one pet. During the attack, Tyler accidentally bumps into a photo of Gayle on the fireplace, knocking it down, revealing the photo of Cleopawtra and Nepurrtiti wearing graduation caps. After one look at the photo, Gayle begins to piece everything together, and the McBrides confess that they forgot about her party because of Cleopawtra and Nepurrtiti's graduation and decided to use the decorations for that party for hers, since they couldn't get any other decorations in time. To the McBrides' surprise, Gayle isn't angry about the situation, saying that as weird as it was, she appreciates that they went out of their way to surprise her.
At night, as the McBrides arrive back home, they discover to their horror that their house is a complete wreck, since Cleopawtra and Nepurrtiti have made the party into a wild one. As the two cats participate in a conga line, Harold decides to call up Madame Furball's Academy to demand a refund (since their lessons in discipline and refinery were all for naught), but Clyde encourages them to partake in the conga line.