Camila Cabello Takes Lie Detector, Reveals Real Reason She Auditioned for X Factor on Carpool Karaoke

While the segment is usually an opportunity to learn a lot about his guest rider, we actually picked up a very interesting detail about James along the ride this time. He has a secret trick he applies to the salsa that is so ludicrous, it actually works.

As he explained it to Camila, the trick is for your face to look like it's started and surprised at what your body's doing. Honestly, we could have watched him and Camila practicing this technique all day.

Camila proved a great carpool buddy, with a great sense of humor and candor about her life. She opened up about her family's early struggles immigrating to the United States. She and her mother came with nothing but what they could carry while her father literally swam across a river to get here.

And yet, despite his dedication, Camila said she couldn't bring herself to invite Dad to her 25th birthday party, even though her mom is invited. James couldn't understand it, but it makes perfect sense to Camila.

She can't have her dad around while she "throws this ass in a circle." But Mom is allowed to come because "she encourages me to throw this ass in a circle."

Surprisingly, Camila made her biggest confession before the lie detector even got into the car, revealing what she said was the real reason she auditioned for "The X Factor" a decade ago.

Waffling between it and "The Voice," she concluded that One Direction would most likely appear on Simon Cowell's show, since he formed them in the UK version of the same show.

Obviously, then, Harry Styles would meet her and be so impressed with her amazing vocal talent that they would wind up falling in love. If this sounds weird, remember she was 15 years old -- so in that regard, the logic is flawless.

The success of One Direction is even the main reason she agreed to be formed into a group of her own on the show, joining Fifth Harmony.

Surprisingly, once he had her strapped down, James didn't ask her anything about her former bandmates, with whom she said she holds no ill will, though she didn't love five voices fighting for creative control.

He did put her on the spot on whether or not current collaborator Ed Sheeran or Harry Styles makes better music. But Camila didn't hesitate to answer that question, passing the test with flying colors.

The three lies the machine caught her on was when she said she wasn't the best looking person in the car -- hilariously used to calibrate the machine -- which was her favorite talk show to appear on, and when she said she hadn't slid into anyone's DMs in a romantic sense.

The journey ended with Camila revealing her go-to karaoke song, which admittedly is an uptempo blast to sing at the top of your lungs, even if you can't sing at all. Showers, karaoke bars, in the car, we feel you, Camila!

To find out which song it is, and hear her sing and laugh her way through her own greatest hits, check out the video above!