The lives of the young and famous become inevitably tangled with every whos-who party and whirlwind romance, and it makes it all the more entertaining when things don't go smoothly.

Kendall Jenner and Hailey Baldwin have been friends for a while now, running in the same model circles and posting updates on their lives together on social media. The pair recently appeared in a trailer for Apple Music’s Carpool Karaoke series, where they paused the music to unearth some very personal details.

Buckled in and strapped up to a lie detector test, Jenner starts easy by asking her friend if she likes her hair, to which Baldwin answers yes. 

Baldwin dives in and pointedly asks, "Have you ever created a fake Instagram to look at what your ex-boyfriend is doing?”

It turns out Jenner is just like every other ex-girlfriend out there, as she replies, "You know the answer to this! Yes!” 

Then, feeling gutsy, Jenner asks the newlywed, "Does Justin think I’m cool?”  A long pause ensues. 

"Of course!” Baldwin replies. The two sit, squirming nervously, until the lie detector administrator says, "That's a lie." 

Baldwin really tried not to throw Bieber, her new husband, under the bus, but the truth could not be restrained.

Jenner didn't seem too upset about it, however, as she shrieked in laughter. She's a longtime friend of both Bieber and Baldwin, even speaking about their engagement on 'The Tonight Show Starring Jimmy Fallon,' saying that she's happy as long as they're happy.