One Direction's Liam Payne takes girlfriend on a date to watch Andy Murray at Barclays ATP World Tour Finals

Since finishing their six-month world tour, One Direction have been making the most of their downtime back home.

And no doubt Liam Payne wanted to spend as much time with his girlfriend Sophia Smith as possible before they head back on the road.

On Tuesday night, the boybander took his lady love on a date to watch Andy Murray play in the Barclays ATP World Tour Finals.

The couple were attending the British tennis champion's round robin singles match against Milos Raonic of Canada on day three at the O2 Arena, where Murray won in two sets.

Liam and Sophia, who is a childhood friend, have been dating since late 2013 and it seems he's still smitten as there is a song on the forthcoming One Direction album written about her.

Though it seems Payne wasn't the one wielding the pen as it was his bandmate who actually wrote the lyrics.

Liam wrote the music to the song called Illusion, and admitted it was 'a bit wierd' that Niall had written the words. 

'There is a song about Sophia and I didn't write it, which is a bit weird,' he said during a live stream with video director Ben Winston.

'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..."' 

Horan was enjoying a night out in London on Tuesday too, though he was at The Palace Theatre to watch the musical The Commitments.

Niall joined the cast backstage following the stage show which tells the story of Jimmy Rabbitte, a young working class music fan, who shapes an unlikely bunch of amateur musicians and friends into an amazing live act, the finest soul band Dublin has ever produced.

Irish affair: He joins the cast of the musical which is set in Dublin's fair city