Wendy Testaburger presents a slideshow of art (Yaoi) drawn by the Asian Girls in at the school assembly. As the slideshow progresses, it is shown that every picture is of Craig and Tweek in a relationship/sexual positions. All of the girls find it adorable but not the boys, especially Tweek and Craig. Afterwards, the boys debate on whether or not Craig and Tweek are actually gay, fearing they could be "next" (have Yaoi art drawn of them).
Craig and Tweek approach the Asian Girls and ask to know why they are drawing pictures of them. Tweek freaks out, exclaiming "What if my parents find out?" They are called in to PC Principal's office. Even though they proclaim they are not gay the Principal refuses to hear their pleas and lectures them on "affirmative consent" rules of engagement, to their annoyance.
Stan is confused by the events that are transpiring, and Randy tries to talk to him about it, saying that as a "PC Dad", he knows all about this stuff. But when Stan asks why Asians are the ones who decide who is gay, Randy is confused and lost, acting like he knows what Yaoi is (describing it as anal intercourse, as well as using unrelated words such as "Maui Zaui").
At Whole Foods, Thomas Tucker is told by numerous people that they know about Craig, and they're happy for him. He is scared and confused as he has no idea what they're talking about.
At dinner at Tweek's house, his parents tell him that they know he's gay, and that they're proud of him. His father becomes so ecstatic that he gives Tweek some money. A musical interlude, "The Book of Love" shows a montage of Tweek, Craig, Thomas and Stan lying in their beds, confused about everything. Outside of the school, there is a giant mural of Tweek and Craig spray painted on the wall. A local artist tent shows off hundreds of Yaoi art of the two, and the Asian Girls are selling the pictures for money. Mayor McDaniels is shown in her office, looking through photos of them, and then glances at a photo of a man on her desk.
In his room, Cartman is trying to make sense of the situation, and Cupid Me shows up and is asked to help Tweek and Craig's supposed relationship. Cupid Me shoots Craig with a love arrow as he sleeps, and then pees in his mouth "just for fun", much to the amusement of Cartman. Cupid Me tries flirting with Cartman, who shoots him down because he claims he is not a homosexual.
The next day, Cartman comes up to Stan and Kyle, telling them that Tweek and Craig are "about to have sex". In reality, they have a fist fight. PC Principal calls Thomas to inform him that Craig had been in a fight, which makes him happy and relieved. PC Principal calls it a "lovers quarrel", but there were no "affirmative-consent issues", which annoys both Craig and Thomas. Instead of disciplinary action, the two are sent home and given money.
Randy calls Xi Jinping the President of the People's Republic of China (PRC) and asks how his people decided who is gay or straight. Xi tells Randy that Yaoi comes from Japan, but Stan walks in and Randy once again pretends he knows what he is talking about. Xi then goes on a rant against Japanese people, calling them "dogs" who refuse to apologize to the People's Republic of China for the Sino-Japanese war crimes (Nanking Massacre) of WWII.
Cartman receives flowers from an anonymous person, attached with a note that says "Can't we just try? TeeHee." revealing that it was Cupid Me who sent the flowers. Cartman and Cupid Me have a serious talk about this one-sided relationship, and Cartman cuts Cupid Me off, claiming still that he's not a homosexual.
Craig shows up at Tweek's house, and tells Tweek that he has a plan to "put a stop to this." His plan consists of: coming out as gay, and then staging a break-up, so that the pictures and rumours will end.
At Skeeter's Bar, Thomas is drowning his sorrows, complaining "why does this have to happen to my son?" Randy then shows up, claiming to know about the situation, on authority of his PC Branded status. Randy then spews a story about World War II, and an event that happened in China called "The Rape of Don King".
The boys look up Yaoi, but are still confused as to why it exists in the first place. In front of the Asian Girls, Craig and Tweek stage their "break-up", but unfortunately, Tweek goes too far and creates a "Michael". Tweek continues and tells Craig he just uses people and steps on them. He runs off in tears, and Wendy follows after him. The Students are disgusted at Craig for "breaking up" with Tweek. Another musical interlude, "Say Something". The plan works, but now everyone is sad about Tweek and Craig "breaking up", and the Yaoi art about them has been replaced with sadder murals depicting Tweek as the victim. The Mayor is seen standing in front of a gravestone, suggesting she is a widow to the man in the picture on her desk.
Cartman shows up at a gay bar called Ruffian's, where he tells Cupid Me that they need him to help Craig and Tweek get back together, which Cupid Me only accepts after the promise of one date with Cartman. It is shown that only Cartman can see Cupid Me, as everyone else thinks he's talking to himself.
Tweek comes to Craig's house and tries to make up with him. He tells Craig that he made him believe in himself more than anyone else has done before, and that everyone is sad now. Craig refuses and points out that Tweek went way too far in the fake break up, and now he'll never get any girls. He then tells Tweek that he's going to have to go be gay with someone else. Inside, Thomas is talking to Laura about how he feels about the whole situation. He says that in his time, homosexuality just wasn't accepted. Cupid Me shows up and shoots Thomas with a love arrow, and pees in his mouth as well. Thomas opens up, and tells Craig that he can't fight being gay, and that he supports him. He then gives Craig $100.
In CtPaTown, Tweek is walking around when Craig shows up. Without saying anything, he extends his hand. Tweek takes it, and they walk down the street together. Everyone sees, and is thrilled about it (except for the other boys). Tweek and Craig are then seen together, playing Assassin's Creed Syndicate as a Japanese man is singing a love song about them while a live action video of two boys dressed like Tweek and Craig walk around.
The episode ends with Cartman and Cupid Me on their "date", where Cupid Me seemingly has anal intercourse with Cartman. His mom walks in on him in the bathroom, imagining their date, while masturbating. She finds it cute.
AV Club gave "Tweek x Craig" a "A-" rating saying: "So if anything, “Tweek x Craig” is critical not of homophobia, but of something much more general, something that’s become the target of many, many South Park episodes since the show first aired: following a trend without doing the research. The only reason anyone thinks Tweek and Craig are gay in the first place is because of the aforementioned erotica, which gets drawn by a bunch of Asian schoolgirls simply because they think the two boys are cute. There’s no logical reasoning behind any of it other than the girls’ own sexual quirks, but that doesn’t stop everyone from taking the romance seriously. And that central joke—an entire community buying into something that’s so untrue and so silly—is a hallmark of South Park if there ever was one. The plot of “Tweek x Craig” isn’t as scathing as it is universal and observant, its lightness also making room for one of the funnier and odder Cartman storylines we’ve seen in quite some time."
IGN gave "Tweek x Craig" a "8.5/Editors Choice" rating saying: "Suffice to say, Tumblr will be aflutter this week, as South Park got about as close to confirming the Craig/Tweek ship as they'll ever get in tonight's episode. Of course, we knew that was never actually going to be the case, but it still made for a fun -- and funny -- episode, along with a surprisingly enjoyable Cartman/Cupid Me storyline. (I'm sure many a Wacom is firing up right now for that romantic pairing too.)"