“forever” is a love ballad directed toward Charli’s current boyfriend Huck Kwong. The song shows how she wants to be in his life forever, even if they eventually drift apart. The song, according to Charli, also addresses the difficulties of the two’s long distance relationship, but maintains how she still feels as strongly as ever for him.

The song was first teased by Charli with a tweet of a screenshot of messages sent to producer BJ Burton. The message Charli sent BJ said:

Ok sick, first song I wanna put out is forever either on April 10th or possibly more realistically on April 13th

She shared a tweet previewing the track’s instrumental the next day and showed some of its lyrical contents in an Instagram live session later that day. It was later premiered by Annie Mac on BBC Radio 1.