Songfacts®:

• Over a pulsating bassline, Chalie Puth cautions himself that he's getting involved in a dangerous and all-consuming relationship. However, the singer ends up ignoring the red flags.
  
  I warned myself that I shouldn't play with fire
  But I can tell that I'll do it one more time
  Don't trust in myself, no good for my health
  You messed with my heart, now you're the reason why
  
  The woman can't be trusted; she told Charlie that she'd left her old boyfriend but it turns out that's a lie. Even though his doubts have been realized, he can't stop seeing her.
• According to Puth, the song is about "a vicious cycle of going back to someone continuously, knowing deep down that they aren't any good for you."
  
  Puth wrote the song on his own and produced it alongside Benny Blanco (Katy Perry's "I Kissed a Girl," Kesha's "TiK ToK," Rihanna's "Diamonds," Justin Bieber's "Love Yourself").