Songfacts®:

• Louis Tomlinson is joined on this electro-pop track by American singer Bebe Rexha. The producer Nick Gale, a.k.a. Digital Farm Animals, also gets a featured credit. The British DJ is best known for his work on Dua Lipa's "Be The One" and Galantis' "No Money" plus his own single with Cash Cash "Millionaire."
• The song finds Tomlinson lamenting about a girl he can't get out of his mind, even though his friends are urging him to move on. Bebe Rexha's lyrics are equally tortured as she explains why she can't let go of their toxic relationship. Tomlinson said:
  
  "We wanted to write something a little less soppy. It's about that one person that, no matter how hard you try, you keep coming back to."
• Even though this is Louis Tomlinson's first solo single it starts with Bebe Rexha, singing the entire first verse. He explained to the BBC: "We recorded a version where I sang first - but you've got to do what's best by the song. With the emotion she gives it, and the way she opens up the song, it always had to be her, really."
• Nick Gale told Billboard the story behind the song.
  
  "I was working with (Manchester-based songwriting collective) The Six, and one of them is a phenomenal keyboardist. We were in a '60s-era mindset, jamming, and came up with that melody."
  
  When Gale heard Tomlinson was looking for tracks, they, "brought it to him and personalized it for what he does."