"Cat Orgy" is the seventh episode of Season Three, and the 38th overall episode of South Park. It originally aired on July 14, 1999. It is set on the night of the same meteor shower as "Two Guys Naked in a Hot Tub" and "Jewbilee", utilizing interlocking story elements.
Shelly Marsh babysits for Cartman while his mom attends a meteor shower party. Shelly's much-older boyfriend Skyler and his band visit. Also, Mr. Kitty is in heat.
Cartman is playing Wild Wild West, and then his mom talks to him. She tells him she has to go to her party and introduces his babysitter: Shelly. After his mom leaves he tells her to put the pizza his mom left him in the oven, but she hits him to his horror.
Cartman is angered by the violence that Shelly displays and how she orders him around. He attempts to phone his mom but Shelly is using the phone.
Later on, Shelly's boyfriend Skyler comes around and Cartman manages to take a picture of them kissing. He goes upstairs, locks the door, and ties the picture to Mr. Kitty who is in heat. She takes the picture away but Shelly manages to get the picture and Kitty runs off.
Shelly tricks Cartman to open the door and drags him downstairs. Skyler's band "The Lords of the Underworld" have arrived and are practicing music. After Shelly performs a song with the band, the band leaves after taking a dislike to her.
Shelly and Skyler go outside to watch the meteor shower, Cartman convinces them to let him come and watch with them. He goes but conceals a tape recorder in his shirt so he can prove Skyler was over, his previous phone call to his mom failed since she didn't believe him.
Outside, Skyler dumps Shelly after she will not let him get any physical love out of her. She is reduced to tears and Cartman reveals he caught her and that she will be caught but she doesn't care. Shelly said that Skyler acted he really cared about her and nobody at her school will go out with her because she's ugly. At first, Cartman said Shelly is not ugly but then admits that she is ugly, but said that Shelly doesn't have to date 22 year old guys because Skyler was a jerk and gross for only dating 12 year olds. Shelly realizes that Cartman is right about Skyler and wants to get him back but doesn't know how, so Cartman decides to help her get revenge.
Kitty has been stalking the streets looking for male cats which proves successful when she finds a group.
Cartman's plan works as he manages to lure Skyler out his house by playing a tape stating Selma Hayek is in need of help. Inside, Shelly smashes Skyler's beloved guitar and sticks it in a pile of kitty litter with the words King Turd spelled out.
At Cartman's house, Kitty has lured all the cats in and they have engaged in a cat orgy, Cartman tries to shoo them out but encounters Skyler upon opening the door. Cartman throws a box of catnip at him and the cats go mad and try to rape him.
Shelly admits she thinks Cartman is okay, and he thinks she is too proving that two people who hate each other can get along. Cartman's mom comes home to discover the house covered in mess from the cats. Shelly and Cartman blame each other for it but she is too drunk to notice. Cartman and Shelly then make up and Cartman finishes by singing his Wild Wild West song.