Songfacts®:

• Ed Sheeran takes aim at his former girlfriiend's new boyfriend on this aggressive breakup song, suggesting his ex has made poor choices as she still has feelings for him.
  
  I don't wanna know about your new man
  'Cause if it was meant to be
  You wouldn't be callin' me up tryin' to
  'Cause I'm positive that he don't wanna know about me
  
  Speaking with Zane Lowe on his Beats 1 show, Sheeran explained that he isn't talking about an actual boyfriend of his ex but the stereotype of the guys that she likes, or at least she thinks she likes.
• Sheeran also recorded a diss track aimed at an ex on his x album. However on "Don't" he gets a lot more nasty, and unlike the former girlfriend on this song, they probably haven't remained friends.
• The song was co-written with Sheeran's fellow English singer-songwriter Jessie Ware, who also supplies backing vocals. Sheeran previously collaborated with Ware on her 2014 single "Say You Love Me."
• The song also has a vocal feature at the end from Francis Farewell Starlite, who is the frontman of the musical group Francis and the Lights. Starlite has previously contributed to songs by Drake ("Karaoke") and Chance The Rapper ("Same Drugs").