Miley Cyrus Admits She Used to ‘Bully’ Hailey Baldwin as a Kid

A-list 20-somethings Miley Cyrus, Hailey Baldwin and Kendall Jenner have known each other for years, and that made for a particularly salacious episode of Carpool Karaoke, which aired Friday.

The Emmy-winning Apple TV show, a spinoff of The Late Late Show with James Corden‘s popular segment, showed what would make a dream girl group cruising around for 18 minutes, singing one of the pop star’s first solo hits, dishing on their childhood and taking a lie detector test. Baldwin, 22, also shared some entertaining details about her relationship with singer Justin Bieber, 24, whom she secretly married back in September.

During the episode, Jenner, 23, also attempted to take her friend for a motorcycle ride — Baldwin was quick to jump out of the sidecar before things really got moving — and they invented a secret handshake.

To start, Cyrus, 26, makes a surprise appearance as the models sing “Party in the USA.” The Disney Channel alum peeks through both the passenger and driver side windows before climbing into the car through the trunk. Then, after they finish their jam sesh, the singer reveals that she used to bully Baldwin because they’ve known each other since they were preteens. Cyrus was close with Baldwin’s older sister Alaia.

“I would be evil to her,” Cyrus recalled. “She would try to play with us, like me and Alaia, and then we would lock her out of the room and be evil.”

The “Wrecking Ball” musician joked that she was just training the future celebrity for life in the spotlight.

“I had to. It made you who you are, you know? It made you stronger,” she quipped. “Now you can always take like … the trolls and s—. ‘Cause I was such a troll.”

RELATED: Hailey Baldwin Returns to Runway for First Time Since Marrying Justin Bieber

Baldwin added, “Miley was the biggest troll to me! She prepared me for this industry!”

The next exciting moment came when Jenner and Baldwin strapped on some heart monitors to take a lie detector test. After getting called out for falsifying her opinion of Jenner’s astronaut-esque zip-up, the newlywed shifted the conversation to romantic relationships.

The Drop the Mic host admitted that she’d snooped through a significant other’s phone, while Jenner one-upped her, saying that she’d created a fake Instagram account to spy on an ex. Then, when the reality star asked her BFF if Bieber thinks she’s “cool,” Baldwin responded, “Of course!”

Even though the lie detector begged to differ, Baldwin insisted, laughing, “I promise you he does.”

Baldwin and Bieber have been flaunting their love all over social media, and now they’re taking their PDA to the cover of Vogue, a source confirmed exclusively to PEOPLE.

RELATED: Kendall Jenner and Ben Simmons Heat Up — But They’re ‘Still Not Exclusive,’ Source Says

The newlyweds were seen participating in a photoshoot last week — and the insider clarified that the pictures of the “Sorry” singer giving the model a shirtless piggyback ride were for the iconic fashion magazine.

“It was the first photoshoot of them together as a married couple. It will be the cover of Vogue,” the Bieber source said. “They wanted to do the cover as a celebration of their love.”

RELATED VIDEO: Liam Hemsworth Scares Miley Cyrus as She Puts on Lipstick

The insider added that the couple will also do an interview because “they want to share with everyone how happy they are, how they make their marriage work and their plans for the future.”

A photographer at the shoot also revealed some details, telling PEOPLE: “The shoot was all day. Both Justin and Hailey were super into taking the pictures. They did multiple outfit changes. Hailey looked so gorgeous, and Justin looked very happy. It was a fun and playful shoot. She was doing cartwheels, and they were both laughing a lot.”