By Joshua Lyon
May 21, 2015 @ 11:30 am

James Corden and Justin Bieber seem to be becoming best buds. First the singer made a surprise, silent appearance on The Late Late Show playing drums with the band last week, and now he’s filmed an episode of Corden’s already classic segment, Carpool Karaoke.

They began with “Baby,” and after they finished the host told Bieber, “I’ve got to be honest, when I picked you up I didn’t recognize you because you had a top on." Which led to a discussion about Bieber’s famous Calvin Klein campaign. “They send me a lot of boxers,” Bieber said. “I definitely don’t wear them twice. There’s so many!”

“That’s the life,” Corden sighed. “I have to turn mine inside out.” After they sang a few lines from “Boyfriend,” Corden turned down the music to take umbrage with the lyric, “Chilin’ by the fire while we eatin’ fondue.”

“Now that’s the line where I’m out,” Corden said. “Because fondue is not a good date food. You end up with cheese dripping down your face!” Bieber tried to make an argument for chocolate fondue with strawberries, but Corden cut him off: “I think you just put 'fondue' in there because it rhymes with whatever.” Click the video above to watch the duo swap outfits and sing Boyz II Men. Bonus: Bieber solves a Rubik's Cube!