Liam Payne and Niall Horan wrote this song with frequent 1D songwriters Jamie Scott, Julian Bunetta and John Ryan. The lyrics are about Liam's girlfriend, Sophia Smith, whom he has been dating since late 2013. Surprisingly, it was Niall, rather than Liam, who penned the words. "There is a song about Sophia and I didn't write it, which is a bit weird,' Liam explained during a 1D Four Hangout chat. "I wrote the melody for it."
"Me and Julian, who we write songs with, were talking, we just went outside for a chat and I was telling him about what happened with me," he added. "After I left, he [Niall] went back and phoned me up like 'Hi, we wrote the whole song about Sophia', and I was like... 'Okay, this is strange...'"