The reigning princesses of pop, Charli XCX and Carly Rae Jepsen who separately crafted two of my favorite songs this year, (“Boys” and “Cut to the Feeling,” respectively,) have teamed up on a song off of Charli’s new mixtape, Pop2, and it good.

“Backseat” is the album opener and features the same kind of perfectly relatable songwriting we’ve come to expect from XCX and Jepsen. On the pre-chorus, we hear both singers wonder, mid-backseat make-out with a guy: “Year in a half, are we in love? / I’ll never know.”

It’s a sadder song than we’re used to hearing Jepsen croon, but it works: Both women meditate on romantic mistakes and losing yourself at a party over a glitchy, propulsive beat, and when you hear XCX say “It’s Charli, baby” at the end, you know she’s properly set the tone for the rest of the mixtape. Listen to “Backseat” above.