James Corden became Taylor Swift’s unwanted substitute dancer in a hilarious Late Late Show bit filmed before the all-star iHeartRadio Jingle Ball concert last week in L.A.

In a new clip that aired during his show Thursday night, Corden got word that Swift had lost one of her backup dancers. He showed up in a fishnet belly shirt and offered to help. “I’ll slot right in,” he said. “Problem solved.” Together, they practiced her Reputation track “Look What You Made Me Do.” Watch it below.

Corden also mingled and goofed around with the concert’s other high-profile artists: taking over as Ed Sheeran’s security guard (using the code name “gingerbread man” for the red-haired singer), giving Niall Horan an awkward massage, encouraging Demi Lovato with a pep talk and weird handshake, cuddling with Liam Payne and forcing Sam Smith to rest his voice.

Keep up with the latest trending music news by following us on FacebookTwitter, and Instagram