"Collide" is the eighth of 14 tracks on Equals
. Sheeran told Apple Music he felt the album was "quite morose" up to then and needed an uplifting song. His first-dance wedding song was Ben Kweller's 2006 tune "Thirteen
," which lists things he did with his wife. Sheeran messaged the American singer-songwriter and asked if he could record a version of "Thirteen" that details things he and Cherry have done. Kweller readily agreed.