"Sleepover" is the first segment of the twenty-second episode of Star vs. the Forces of Evil. It premiered on September 26, 2016 alongside "Gift of the Card", and is the first segment of the ninth episode in the second season.
Star is holding a sleepover at the Diaz house with Pony Head, Jackie-Lynn, Janna and StarFan 13. After having a batch of terrible brownies, they witness Marco attempting to be cool by playing a synthesizer. Pony Head quickly picks up that he is doing this to impress Jackie-Lynn so she suggests that they all sit down to play Truth or Punishment, a sinister sounding version of Truth or Dare. Marco is reluctant to play it, but Star gets him to settle down with them in her bedroom. They turn on the box and it comes to life. It has them pinkie swear (or in Pony Head's case, tongue swear) that they will always tell the truth no matter what. The box asks the first question: What is your favorite color? Pony Head says "Pony Head color" (which according to Star is popular on Mewni), Star says yellow, to which StarFan 13 concurs, Jackie-Lynn says neon green, Marco says red and Janna says black (which Jackie-Lynn says is her second favorite). The box states that someone is lying and electrifies them into laughter. Janna breaks and admits that her favorite is pink as she does not like to conform to gender stereotypes.
The box expands and encases Star's loft on the house which Star finds awesome, but concerns Marco. The box asks the second question: What did you really think of Star's brownies? Star claims that everyone loves them which everyone agrees to, minus Marco because he did not try them. Everyone's faces suddenly deform with the box claiming that this is what lying looks like. As Marco was telling the truth, he demands that everyone comply. Janna, Jackie-Lynn and Pony Head admitted that they hated Star's brownies. StarFan 13 claims she liked them, but when they all mutate further, she buckles and admits that she too disliked them. Pony Head apologizes for bringing the game for them to play and they all attempt to exit to the Bounce Lounge, but the box keeps them inside and demands that they finish the game.
The box asks the final question: Who do you have a crush on? Everyone settles to answer honestly. Jackie-Lynn says she liked a guy from skate camp last summer, Star says Oskar Greason, StarFan 13 says Star Butterfly, Pony Head says herself, Janna says 18th century poet John Keats and Marco, in a solemn display of affection, admits that it is Jackie-Lynn Thomas, surprising her. The box claims that someone lied. Marco breaks down further and says that he does not know if he just likes her image, but he wants to get to know her better. The box is amazed at Marco's honesty, but says that he is not the liar. He transforms into a monster and attacks the group claiming that liars need to be removed, but Star explains that most people do not know their own truths admitting that blue is her favorite color right now and Jackie-Lynn admitting that she does not know who she has a crush on. The box deflates and returns everything to normal.
The box is tossed out with the rest of the garbage as Pony Head, Janna, StarFan 13 and Jackie-Lynn all head home with the latter happily telling Marco that she will see him at school. Marco overcome with love, tells Star that he will catch up on sleeping due to the night's events, confusing Star. As the garbage man takes the trash and tosses it into the compactor, the box springs to life declaring that Star was the one that was lying. He is about to spout out who she really has a crush on, but gets destroyed by the compactor before he could reveal the identity.
- Eden Sher as Star Butterfly
- Abby Elliott as Janna Ordonia
- Adam McArthur as Marco Diaz
- Grey DeLisle as Jackie-Lynn Thomas
- Daron Nefcy as StarFan13
- Jenny Slate as Pony Head
- Sean Schemmel as Box of Truth
- Marco reveals to Jackie Lynn Thomas that he has a crush on her.
- The end of the episode strongly hints that Star has a crush on Marco before the cube was crushed.
- Star is revealed to be terrible at making brownies.
- Aside from the fact that StarFan 13 likes anything Star Butterfly related, it is possible that she has a legitimate crush on Star, making her character LGBTQ.
- October 20, 2016 (United Kingdom and Ireland)
- November 17, 2016 (Italy)
- December 15, 2016 (Israel)
- January 12, 2017 (Poland)
- February 5, 2017 (Japan)
- February 16, 2017 (Spain)
- March 7, 2017 (Latin America)
- April 14, 2017 (Southeast Asia)
- October 5, 2017 (Portugal)
- March 10, 2018 (Philippines)