It was released on 22 July 2015 in the United Kingdom by TEN Music Group, Virgin EMI and Epic as the second single from Larsson's second studio album So Good (2017).

The song peaked at number one in Larsson's home country as well as the top ten in eight additional countries, and became both Larsson and MNEK's first US entry on the Billboard Hot 100, peaking at number 13 in May 2016 and becoming the best rank on the chart for both artists.

An orchestral version of the song was later released on 21 May 2021 as a track off the Summer edition of Larsson's third studio album Poster Girl.

It shows the girl growing up and always thinking about and spending time with the creature, or imaginary friend (played by Chris Fleming).

The video was filmed in Iceland and was directed by Richard Paris Wilson.