Songfacts®:

• Sheeran wrote "Nina" with Snow Patrol's Johnny McDaid. The pair first got together in 2013 in Nashville to work on tracks for Sheeran's x album. "The first song we wrote together was 'Nina,' a love song about heartbreak, both self-inflicted and otherwise, where he basically calls someone up and advises her not to be with him," McDaid told Billboard magazine. "That sort of self-deprecating diary is pretty honest. Most people are fearful of being naked in front of the world, and afraid to expose their weaknesses. Ed isn't."
  
  The pair became close friends and moved to Los Angeles together to continue working on x. Sheeran introduced McDaid to Courteney Cox, who became the Snow Patrol member's girlfriend.
• Sheeran penned this song about the Scottish singer-songwriter Nina Nesbitt, who toured with him and also had a small cameo role in his "Drunk" video. The pair were also romantically involved for about a year. Sheeran explained during a Spotify track by track: "When you're a musician and you date someone, there's always an in-between. Like, you put your family and your friends first, always, and then your career second. But when you date someone, they kind of fall in between the family and friends and career, and you don't really know whether they're more important than the career or whether they're more important than family - so this is a song about that."
  
  "You just need to find someone that's OK with it, and I think by the time you have kids, that's when your family comes first, and that's where the woman comes, because she's your family now," he added. "I think kids change everything, but up until then it's different. My family understand I had to go away for 12 months last year, but until you find a partner who'd happy with that, you shouldn't even bother. Well, you shouldn't bother committing."
• The song is based on a sample of the piano from Wretch 32's "Welcome To My World," which is a track from the British rapper's third mixtape, Retrospective.
• During a 2024 episode of The Eras Podcast, interviewer Abbie McCarthy asked Nina Nesbitt about having a song written about her. When specifically mentioning Ed Sheeran's "Nina," McCarthy inquired, "Did it bother you?"
  
  Nesbitt acknowledged that it's inevitable for personal details to seep into an artist's music. "I think it's just got to come out," she explained. "There should really be a disclaimer on songwriters."
  
  Being the subject of Sheeran's song proved "tricky" for Nesbitt, as she didn't want to be primarily known as someone's ex-girlfriend. Despite the positive opportunities that came with touring with Sheeran, she expressed frustration with the constant references to their past relationship in articles about her music.