|Original broadcast||March 11, 2011|
|Series||Ben 10: Ultimate Alien|
|Overall episode number||123|
|Written by||Eugene Son|
|Directed by||Dan Riba|
|Previous episode||The Big Story|
|Next episode||Revenge of the Swarm|
Girl Trouble is the twenty-fifth episode of Ben 10: Ultimate Alien.
The group go to Gwen's house in order to find a solution to stop Computron's minions from Dimension 12. When they go inside her room, they already find another girl on her bed. It turns out to be Sunny, a cousin of Ben and Gwen.
Gwen tries to persuade her mother to get rid of Sunny, but she explains that Sunny is staying over the summer because her parents want her to be around a good influence, like Gwen. Sunny tries to flirt with Kevin and is forced to go with them to stop an invasion of Dimension 12 robots, annoying all of them during the car ride. When they arrive at the location the robots are appearing, they fight them. Sunny sees the commotion happening and gets out of the car to see. She then reveals her Anodite powers and destroys the rest of the robots, shocking everyone.
Natalie is informed of Sunny's Anodite powers and thinks of whether she should stay or not, considering her dislike for Anodites. Suddenly, they get a visitor and it is revealed to be Sunny's boyfriend Antonio, who she always kept talking about, but Antonio is really a giant, caveman-like alien with little intelligence.
Sunny decides to run away with Antonio and before they could go after them, Ben informs Gwen of another attack of the Dimension 12 robots. The robots have a plan to use a particle accelerator on a small canister bomb to make its energy levels stronger in order to destroy Earth. Ben transforms into Lodestar and they attack the robots again, before Sunny and Antonio join the fight.
Kevin shuts down the particle accelerator by smashing its control device and when they try to get Sunny to go back home, Sunny refuses to and sheds her human skin, revealing her Anodite form. When Gwen threatens to tell Sunny's parents about her misbehaving, a fight ensues. Gwen fights Sunny, Humungousaur fights Antonio and Kevin is in charge of making sure the upgraded canister bomb doesn't blow up and destroy them all.
Sunny overpowers Gwen and Antonio's strength is too much for Humungousaur, so he transforms into Ultimate Humungousaur and quickly gains the upper hand, while Gwen calls her grandmother Verdona through the mana field.
Ultimate Humungousaur tricks Antonio by picking up an unlit light post, while Antonio picked up a lit light post that electrocuted and knocked him out. Kevin disarms the bomb by pulling its cord. Before Sunny could finish off Gwen, Verdona arrives and overpowers Sunny, trapping her in her own shield.
Verdona also takes the unconscious Antonio, and says that their parents are going to sort out everything. Verdona says goodbye and claims that Gwen's powers have developed well, considering the lack of formal training, citing the fact that Gwen was able to contact Verdona via the mana field and offers her another chance to go to Anodyne with her to practice her powers, but Gwen turns the offer down again. Verdona leaves with Sunny and Antonio and the group go to clean up the robots' mess from the battle against Sunny and Antonio.
- Ben and Gwen meet their Anodite cousin, Sunny.
- Verdona and Natalie Tennyson make their Ultimate Alien debuts.
Kevin: (mimicking Gwen) "Kevin, shut down the particle accelerator! Kevin, disarm the fusion bomb!" (in his normal voice) If this thing blows up, I'm never speaking to those guys again.
Kevin: She's pretty powerful. How come you can't do that?
Gwen: Because...SHUT UP!
Gwen: Kevin, can you shut down the accelerator?
Kevin: I don't know, you need like a P.H.D. to use one of these things.
Naming and Translations
|Portuguese (Brazil)||Garota Problema||Girl Trouble|
|Spanish (Latin America)||Batalla Entre Primas||Battle Between Cousins|
|Spanish (Spain)||Chica Problematica||Ploblematic Girl|
- In one scene, the black ten emblem on Ben's jacket is white and the ten is black.
- If you look closely when Antonio is throwing Humungousaur, Humungousaur's toes are the same color as his scales.
- When Ben transforms into Lodestar, his voice was higher than usual and his eyes are bigger than usual.
- When Kevin is trying to stop the bomb from becoming more powerful, the on-off switch look alike, both set to the off position. As soon as the camera changes to a few frames before Kevin smashes the machine, one switch is set to on.
- In the transformation of Four Arms, in one part he has three fingers on each hand.
- When Ultimate Humungousaur fired his missiles at Antonio, the missiles didn't explode.
- This episode reveals that Ben and Gwen have another set of aunts and uncles, specifically on their grandmother's side.