Tove Lo and Shellback penned the song with Ludvig Söderberg and Jakob Jerlström in a basement studio during a Swedish snowstorm.
The track started with a guitar melody played by Shellback on guitar, over which Tove Lo began singing the phrase "glad he's gone."
"It kinda just came out and we all started talking about what that would mean," she recalled to Billboard
, adding with a laugh, "It could be a murder-y song, which would feel really dark, and not really the point of it."
As Tove Lo was personally "happily in love" at the time she penned the song, she began to think instead about friends ending bad relationships. "We all have friends dating an idiot that we want them to get rid of," she said. "It's just a celebration when they finally pull the trigger on that, but you still need to be the supportive friend and give them the love and support that they need."