Demi Lovato - Really Don't Care Lyrics Meaning

I believe that this song is about Demi's former best friend, Selena Gomez. In the lyrics she says, "even if the stars and moon collide, I never want you back into my life." Which I think is a reference to her old song "Two Worlds Collide" which was dedicated and made for Selena. Now she just flipped that song around and singing it in the opposite way. Although, I hope the song isn't for her because Delena is my otp