"The Ex" is the twenty-fifth episode of Season 5 of The Amazing World of Gumball. It is the 181st episode overall.
Important details about the plot or story are up ahead
This episode begins in Dinner in Elmore Mall where Gumball and Penny are having a date, eating ice cream. Gumball assumes that he cannot get brain freeze, but before he can finish his statement, he does, and Penny has to un-freeze him in the bathroom. As the two walk out, Gumball sees Rob at the hardware store and gets excited, asking if Penny knew about him which, as revealed by Gumball talking about his nemesis constantly in a series of flashbacks, she does. He tells Penny to relay him what Rob is doing, though it seems to indicate contrary to the notion of him wanting to terrorize Gumball.
Gumball then gets a threatening message from Rob, though it turns out the message was actually intended for Banana Joe. Gumball tries to rationalize the text as a mistake and confronts Rob, who reveals that he no longer wants to be Gumball's nemesis, instead opting to pursue Banana Joe because he is easier to hate.
The next day, at the Watterson's house, Penny tries to console Gumball about Rob's new nemesis relationship, but Gumball refuses to accept the reality. As they speak, the doorbell rings. Gumball assumes it to be Rob and, despite Penny trying to stop him, meets Rob at the front door regardless. It turns out that Rob wanted to return Gumball's stuff to him, hurting Gumball even further. As Rob walks away, Gumball tries to serenade him by holding a boombox with a song he once hated, though it does not work, and Rob does not hate the song as he once did.
The scene cuts to Rob spying on Banana Joe, ready to destroy him with a trap, but before he can do so, Gumball appears and distracts him. Rob tries to ignore Gumball's pleas for attention, but as he is about to cut the rope of his trap, Gumball takes his scissors, thus ruining the whole plan. The trap fails, but instead of yelling at Gumball, he leaves, making Gumball feel disappointed.
Next, Rob goes to Joyful Burger to give Banana Joe a burger rigged with explosives. Rob waits for Banana Joe to eat the burger, but he repeatedly stalls, much to Rob's chagrin. As Rob waits, Gumball appears dressed/put in a banana suit by himself/disgusing himself as Banana Joe. He assumes that Rob hates Banana Joe because he is annoying and tries to level the playing field by mimicking Banana Joe and noisily sucking a straw. Still ignored, Gumball tries to push Rob even further by doing the Banana Dance. It instead captures the attention of Banana Joe, who gives Gumball a letter stating that, by doing the song and dance, he was breaching on intellectual property rights. Rob gets mad that Banana Joe did not touch the burger or allow him to deliver his quip. In an attempt to appease Rob, Gumball frantically eats the burger, subsequently exploding.
Back at the Watterson's house, Gumball complains about how all the cool people have nemeses. Darwin brings up the fact that he has one of his own: a hat. Penny tells Gumball he should simply accept it and turn over a new leaf, becoming friends, though Gumball steals the words right out of Penny's mouth, declaring them his own, and sets out to unite with Rob.
At Banana Joe's house, Rob is spying on Banana Joe with binoculars when Gumball pops up in front of him. He asks Gumball why he was here, and Gumball states that he only wanted to help. Rob decides to take up Gumball's offer. Gumball then tells Rob that he had booby-trapped Banana Joe's house, much to Rob's excitement, though it instead turns out to have been Tobias'. Rob then reveals a trap of his own: he had rigged Banana Joe's front door handle beforehand so that when Banana Joe opens the door to take out the trash, it will unhook the latch of a truck, sending oil barrels hurling towards him. Right as the plan is in motion, however, Gumball takes out his phone to snap a picture, but instead turns on the torch by accident, causing Banana Joe freeze in place. The oil drums hurdle by Banana Joe, leaving him unharmed but in shock.
Rob gets angry and he tries to shut off Gumball's phone, but quickly hides when Banana Joe approaches. Banana Joe asks what Gumball was doing behind a bush, and Gumball says that he was just chilling out with Rob. Rob emerges from the bushes, angry. He finally snaps and screams at Gumball in anger, declaring him the most insufferable, annoying, selfish person that he had ever met. He proceeds to throttle Gumball, much to his delight.
At school, Gumball tells Darwin that he just needed to keep the hatred interesting. He also tells him about how he smoothed things over with Penny, having locked Alan in her locker and written apologies all over him and her stuff. Seeing that Darwin has the hat on, he congratulates him on having smoothed things out as well. However, it turns out that Darwin was completely unaware of the hat and freaks out when he discovers it, ending the episode.
- Mrs. Fitzgerald
- Penny's Sister
- Brown Oval
- Exercise Bacon
- Yellow Guy
- Banana Barbara (voice)
- This episode and "The Gi" are tied for shortest episode title so far, with only 5 letters.
- It is unknown if Rob really did re-establish his hate for Gumball or if he did it simply out of anger.
- Music from "The Nemesis" is reused.
- In the montage of Gumball talking to Penny about Rob, he specifically refers to events in "The Nemesis" and "The Bus."
- Rob recalls the events of "The Rerun."
- While taking out the trash, Banana Joe whistles the same tune from "The Banana."
- A Laserheart comic book from "The Comic" appears in Gumball's locker.
- This episode marks Penny's eleventh major role. The other 10 were "The Pressure," "The Party," "The Date," "The Knights," "The Flower," "The Dream," "The Shell," "The Bros," "The Romantic" and "The Misunderstandings."
- Gumball references Banana Joe's Banana Dance.
- This is the third time Gumball goes on a date with Penny. The first two were in "The Burden" and "The Misunderstandings."
- This is the twentieth time that Gumball's underpants are revealed.
- This is the seventh time Darwin is seen wearing pants.
- The song at the end when Rob was lashing out at Gumball is a reference to Whitney Houston's "I Will Always Love You."
- Gumball holding up the boombox is a reference to the 1989 movie Say Anything where the protagonist fails to win back his ex by holding up a boombox.
- When Gumball is talking about the "creepy ginger dude" who followed the "wizard boy" and never helped, he refers to Ron Weasely and Harry Potter respectively from the titular series Harry Potter.
- Gumball uses the phrase "Ay caramba!," Bart Simpson's famous catchphrase from The Simpsons.
- Gumball also says "Watcha doin'?," which is Isabella's famous catchphrase from Phineas and Ferb.
- The bike that Gumball wants Rob to cut the brakes on does not have brakes.
- The cup that Gumball reaches for, while dressed as a banana, does not appear in previous shots.
- Though only 4 oil barrels fall out of the truck, 5 are seen rolling by Banana Joe.
- When Rob angrily grabs Gumball, the static on his arms disappear, making his arms look plain grey.