The song started off with a guitar part Goulding was playing around with at a Los Angeles studio with producer Savan Kotecha. The English singer recalled to Billboard
that the genesis of the song's tempestuous love story came when she started singing "don't let me down."
Asked what inspired the lyrics, Goulding explained that Kotecha "gets very overwhelmed with what's happening, particularly in America," and the pair decided they needed to escape for a while and "write something a bit silly." So they came up with "a song about a turbulent, probably doomed relationship - someone to forget the world with."
Goulding decided there was something missing so she sent their demo on to Diplo. "I could tell he was massively into it, because he sent it back pretty much straight away," she said, "He must have worked on it all night."
It was Diplo who then suggested that Swae Lee could contribute a verse.