Selena Gomez is so done with Justin Bieber — and her new single, “It Ain’t Me”, proves it!

In her new song, the 24-year-old sings about leaving her past (a.k.a. her ex-boyfriend) behind. In the song — which features Kygo — she croons, “I had a dream, we were back to 17/Summer nights and liberties, never growing up/I’ll take with me the Polaroids and the memories, but you know I’m gonna leave behind the worst of us.”

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Throughout the chorus, she also asks, “Who’s going to walk you through the dark side of the morning? Who’s going to rock you when the sun won’t let you sleep? Who’s going to drive you home when you’re drunk and all alone?” If you couldn’t guess — the answer is, “It ain’t me!”

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This comes hours after Selena’s new boyfriend, The Weeknd, dissed the Biebs in a track of his own. Shortly after Justin called the “Starboy” singer’s music “wack,” the singer — whose real name is Abel Tesfaye — reclaimed the diss, crooning, “Haters gonna say this sh-t is wack… I think your girl, think your girl, fell in love with me.”

Selena and The Weeknd have gotten serious since first being linked earlier this year. As Life & Style exclusively revealed, the two are even moving in together.

“They’ve been talking to a realtor friend who is quietly looking for properties for them and constantly sending them listings,” a source tells Life & Style, adding that Sel plans on footing the bill for their “love nest.”

Scroll through the gallery to see Selena’s former relationships!