Songfacts®:

• The phrase "flogging a dead horse" refers to wasting energy on a lost cause. Here, Hayley Williams talks about a relationship that she should have abandoned long before she actually did.
• The relationship Hayley Williams is referencing is with New Found Glory guitarist Chad Gilbert. It began as an affair back in 2008, when she was 18 and he was married to Eisley vocalist Sherri DuPree-Bemis. They got engaged on Christmas Day 2014 and married 14 months later, but split up in the summer of 2017 after Gilbert cheated on Williams.
• During the song, Williams comes clean about getting involved with a married man and her shame of what she did to Sherri. After getting married to Gilbert, she tried her best to make the relationship work only for her husband to betray her.
  
  And after all, it's only fair, yeah
  I got what I deserved; I was the other woman first
  Other others on the line
  But I kept trying to make it work
  
  Their relationship lasted much longer than it should have, but in the end Williams was flogging a "dead horse."
• Speaking to Rolling Stone, Williams admitted to feeling guilty throughout her 20s about the way her relationship with Gilbert began. Now, being able to admit it makes her shame less scary. "It gives people a chance to actually know me and decide if they like me or not," she said.
• Hayley Williams has written about Chad Gilbert before on several Paramore tracks.
  
  On "All I Wanted" she recalls her insecurities bubbling up when Gilbert goes on tour for the first time after they started their relationship.
  
  "Still Into You" is a love ballad where Williams discloses there's not a day she's not into her beau.
  
  On "Be Alone," she recounts her desire for Gilbert's company after moving to Los Angeles to record the Paramore album.
• Williams wrote nearly all the lyrics for the tune during a flight. She explained in an Instagram post that it is one of the few songs she top-lined for the Petals for Armor album, rather than building it from scratch. She added: "It really gave me a place to put some haunted thoughts I'd carried for far too long."
• The intro is from a voice note Williams sent her co-writer Daniel James from her bathroom to show him the parts for the song that she'd written.
• Hayley Williams admitted to Billboard that when she wrote "Dead Horse," she "was very surprised that something that pop-y would come out of me."
  
  Williams was embarrassed about some of the lyrics and initially planned to shelf the song. The Paramore frontwoman eventually decided that rather than stifling her creative process, she should follow her muse and release the track.