South Park Elementary holds a cultural diversity event in which Kyle gives a report on the role of Latinos in American technology. A board of Latino community leaders (who are the judges) seem pleased with Kyle's report. Cartman goes on stage to report on the effect of Latino culture on the arts in America. He says he has a special guest, Jennifer Lopez. However, it turns out to merely be a ventriloquist act with Cartman's hand acting as the head of "Ms. Lopez" (reminiscent of Señor Wences) who is a Hispanic stereotype in every way. Despite this offensive display, the judges inexplicably give him first place for having the best report, and he wins a $20 gift certificate at the mall. This angers Kyle, as he thinks Cartman's speech is racist and immature, and because while Kyle had spent weeks laboring over his speech, it is implied that Cartman spent very little time in preparation.
Cartman further enrages Kyle by insisting that "Ms. Lopez" has a mind of her own. When the children go to the mall, Cartman—at the apparent behest of "Ms. Lopez"—pays ten dollars to record a music video at a recording store. The video gets sent to the record company, proving a success and propelling "Ms. Lopez" to stardom. However, the executives agree that "Ms. Lopez" has too many similarities to the actual Jennifer Lopez and decide to replace the more difficult human performer with the puppet because they cannot have two Jennifer Lopezes.
When the actual Jennifer Lopez learns she is being fired, she is infuriated, especially when she learns that her job has been replaced by a puppet. Jennifer Lopez and her husband-to-be, Ben Affleck, show up at South Park Elementary in a limousine. Lopez starts to beat up Cartman's hand until he pleads that he will stop his ventriloquist act. As the two celebrities leave, Affleck catches sight of "Ms. Lopez" and falls in love with her. Tension between Cartman and the hand-puppet escalates as "Ms. Lopez" forces him to do things her way. As the episode progresses, the relationship between Cartman and "Miss Lopez" begins to grow more surreal, with Cartman and "Miss Lopez" arguing (with both their voices being heard simultaneously) and "Miss Lopez" acting independently while Cartman is asleep.
Affleck invites "Ms. Lopez" for a ride in his car. Cartman reluctantly agrees. Later "Ms. Lopez" lets Ben make out with her, then she performs oral sex on him. Cartman looks down, sees what "Ms. Lopez" (his hand) is doing, and, infuriated, departs the car quickly. The next morning Cartman awakes to find in his bed a naked Affleck, who announces that he and "Ms. Lopez" made love all night. Cartman exclaims "AWWWW, Ben Affleck's spooge!" (This line is stripped from the TV-14 syndicated version.)
The news of the wedding again angers the actual Jennifer Lopez as she attempts to kill "Ms. Lopez". Cartman runs. On a bridge, Jennifer Lopez, the police, Ben Affleck, the people from the recording company, Kyle, Kenny and Stan catch up with Cartman and "Ms. Lopez". Everyone (except the boys) starts to argue about "Ms. Lopez". "Ms. Lopez" screams for everyone to be quiet. Cartman removes her hair and "Ms. Lopez", in a male voice, makes the confession that her real name is Mitch Conner, a con man who has been moving around from town to town. Conner apologizes to Ben for playing with his heart and states that he will die because he has recently consumed a cyanide pill. Conner then "dies" (Cartman makes it look like he "flutters away" into the wind), and everyone goes away except for the boys.
Kyle then asks Cartman to explain Mitch Conner. Cartman says, "Look, I don't care what you guys believe. But with all the crazy stuff that goes on in this town, isn't it possible, just possible, that something I don't understand happened here?" When Kyle admits that it's possible, Cartman starts singing, "Ha ha ha ha haa haa! I got you, kinda! I got you, kinda!" Much to Kyle's dismay. The episode ends with Jennifer Lopez working at a La Taco restaurant while on probation. She complains she had six platinum records and starred in five Hollywood movies. The Mexican worker next to her responds "Yeah. Me too."