Songfacts®:

• Kelsea Ballerini's friendship with Halsey began in the summer of 2018 when the pop singer played Ascend in Nashville. The country star went backstage afterwards and the pair immediately clicked. They hung out all night and ended up at Ballerini's place, which is where Halsey played her an early version of "Without Me."
  
  Ballerini loved the idea of having a female collab, but it needed to be with someone she is close to. "I only want collaborations if they're my friends," she explained to Taste of Country Nights. "I don't wanna go to some pop star that I don't know, I don't wanna go to some country person that I just want their people to listen to me - I just wanna do it if it makes sense to me."
  
  Two months after she'd first met Halsey, Ballerini was in Los Angeles, and she played "The Other Girl" to her new pal. "I just played it for her and she dug it, which was cool," she recalled. The rest is history.
• The pop-meets-country besties duet is about a man who's two-timing both females, leaving them to wonder which one of them is "the other girl."
  
  During the first verse, Ballerini imagines who her love rival is.
  
  I bet you're bold
  I bet that's why you seem to occupy his mind.
  I bet you're smart - but do you know about me?
  
  Halsey wonders on the second verse who her romantic competitor could be.
  
  Are you the one he's talkin' to
  When he gets up and leaves the room?
  He comes back with a distance in his eyes
• Halsey told The Boot she found it refreshing to be singing a song about a cheating man where the two women he's seeing aren't tearing strips off each other.
  
  "There's so much music - and I'm partially responsible for this - but there's so much music in the world about cheating partners. People wanna pin it on the other girl, and make it the other girl's fault," she said. "So it was so cool for us to be coming together and being like, 'You know what? Forget him. We're not gonna hate each other.'"
  
  "To be clear, this is a fictional event," Halsey added. "But just us representing those two sides of women in the equation, being like, "No, we're not gonna let misogyny turn us against each other, instead we're empowered."
• Ballerini shared on Twitter that the day Halsey recorded her vocals for this song, she played her "homecoming queen?" and Halsey played Ballerini "You Should Be Sad."
• Ballerini wrote "The Other Girl" with Shane McAnally and Ross Copperman on the tour bus when she was supporting Keith Urban, McAnally recalled to The Boot:
  
  "That song just came from a track that Ross Copperman built, and what happened was when we stumbled into the idea of it almost being like a modern-day 'Does He Love You' [Reba McEntire and Linda Davis' 1993 song], which we loved. It turned into a back-and-forth, and Kelsea knew very quickly - she was like, 'I want to send this to Halsey.'"
• Kelsea Ballerini told American Songwriter that she did her vocals on the tour bus while Halsey contributed her parts remotely from a Los Angeles studio. "If you isolate my vocals," Ballerini said, "You can hear the bus rumble."