Hailey Baldwin Lies About Justin Bieber During 'Carpool Karaoke' with Kendall Jenner
Kendall & Kylie's Sexy Yeezy Shoot

The two take a lie detector test and Hailey's answer to this question sets off a red flag.

Hailey Baldwin is a big fat liar!

The model/Justin Bieber's fiancee joined Kendall Jenner for a new episode of "Carpool Karaoke: The Series," where the two got attached to a lie detector test for part of the segment.

Before hitting the road, the two stunners lobbed a series of questions to each other, as a man in the backseat revealed whether they were telling the truth or not.

The Qs included things like, "Do you like my hair like this?" and "Have you ever created a fake Instagram to look at what an ex boyfriend is doing?", before Kendall asked her friend, "Does Justin think I'm cool?"

Baldwin, who showed off her huge engagement ring throughout the video, told her, "Of course" ... but the man in the back said otherwise.

The rest of the preview for the new season included highlights of other episodes, including sneak peeks at The Muppets driving around with Jason Sudeikis, Matthew McConaughey and Snoop Dogg and Jamie Foxx with his daughter, Corinne, before ending with Kendall and Hailey rocking out to Panic! at the Disco's "I Write Sins Not Tragedies."

New episodes are now available for free on the Apple TV app.

PFW Getty Kendall and Bella Slay in Red at Paris Fashion Week