Taylor Swift and Harry Styles are certainly a thing of the past after their two-month relationship bitterly ended in January 2013 while they were in a Caribbean getaway. Since then, the two have been decidedly cold between each other. However, Harry's One Direction bandmate Niall Horan's weekend sighting at a Taylor Swift concert has swirled some new feelings from the fans. The weekend "date" comes as Horan's two-month romance with the gorgeous Hungarian Victoria's Secret model, Barbara Palvin is reported to have been over.

Harry Styles was in sunny California, happily celebrating his 20th birthday while thousands of miles away, his bandmate Niall Horan was seen busy, hanging out with Harry's ex-girlfriend, Taylor Swift. The 20-year-old Niall flew over to London to be at Taylor Swift's concert at the 02 Arena on Sunday night. He was seen on crutches after his knee operation.

However, in spite of his condition, Horan seemed to feel it was important to support the country singer as she danced around in her hot outfit during the most recent leg of her worldwide Red tour. The One Direction singer was photographed by shocked Directioners at the gig side of the stage with some friends. This is just in time after Horan's short-lived romance with Palvin was rumoured to have cooled, following her relocation from London to Paris to focus on her career.

The new and mind-blowing friendship between Niall and Taylor has raised eyebrows among One Direction fans, who are likely now asking "How would Harry react to this?" or "will this deepen the said cold war between Harry and Niall?" or "Why is Niall at Taylor's concert?"

Niall could be there as a friend or a fan but it is also possible that he was checking out Taylor's duet performance with the British singer-song writer, Sam Smith of "Money On My Mind." An insider told mirror.co.uk that "Taylor is happy to give Niall some Access All Areas passes and even had drinks with him before the concert."

"Taylor and Niall met through their mutual friend, Ed Sheeran. Niall seemed to be a genuine fan of Taylor's music but he smirked when she sang "I Knew You Were Trouble," which was said to be about Harry," the source added.

Niall gave no hint of his appearance at the show, tweeting only about the Super Bowl: "Watching the Super Bowl! And all I can think of is: I can't believe we are playing that stadium in the summer. Mind blowing s**t."