No matter how much time you spend with someone, there are some secrets you might never uncover — that is, unless you’re Brie Larson and Samuel L. Jackson.

The Captain Marvel costars joined forces for an upcoming segment of Carpool Karaoke: The Series (airing in full on Friday), which they began by belting out Ariana Grande‘s “7 Rings.”

Jackson, 70, then pulled up to a house under the guise of wanting to “work on that bond [and] trust between the two of us,” he told the actress. “I got a friend I want to pick up before we get to doing that, and it’s gonna be dope.”

A polygraph examiner, John, then joined the duo in the car and immediately wired up Larson, 29, who looked nervous to be undergoing the impromptu lie detector test.

Jackson’s first question? “Would you be honest with me if you didn’t like my performance in a scene?” he asked, to which Larson replied, “No!” — an answer John marked as true.

RELATED: REVIEW: Brie Larson Flies High as Captain Marvel in Playful Superhero Adventure

Continuing his line of questioning, Jackson learned that Larson doesn’t actually like his Kangol hats or think he has a “strong singing voice” according to the lie detector, despite her animated insistence to the contrary.

The Room Oscar winner then turned the tables, taking the wires off and transferring them to her costar before asking him a hard-hitting question: “Do you like the Captain Marvel suit?”

“Yours? Yeah,” replied Jackson, which John confirmed as true — as well as Jackson’s “Oh hell yeah” about whether he’d be honest about not liking Larson’s performance in a scene.

And finally, the moment of truth: “Have you ever farted while filming a scene?” Larson asked.

RELATED VIDEO: Meet Captain Marvel’s Adorable (and Scene-Stealing) Cat Goose

Without hesitation, the Pulp Fiction actor responded, “All the time” — a claim that ended up being true, according to examiner John from the backseat.

“We’re bonded now,” Jackson said, and the duo shared a fist bump in solidarity.

“Did you fart while we were doing this?” Larson asked

And although her costar replied, “Of course not!” John jumped in almost immediately with, “That’s a lie.”