One Direction's Niall Horan has written a track about Liam Payne's girlfriend which will feature on their new album, Four.

Don't worry Directioners, this is not a case of the Mullingar native taking the lyrics of One D's current single, Steal My Girl, too seriously – it's all in the name of music.

Explaining the situation 21-year-old Payne, who has been in a relationship with Sophia Smith for the past year, said: “There is a song about Sophia and I didn't write it, which is a bit weird.

“I wrote the melody for it. It's called Illusion. 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.

"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...’”

Illusion will feature on the One Direction's new album, Four, which is set for release next week.