Taylor Swift welcomed British singer Robbie Williams to the stage during her concert Saturday night in London.
Swift, sitting at a piano, started performing Williams’ hit “Angels” before he came out to join her.
“What an honour to sing with you tonight,” Williams tweeted later. “I’ve got a proper crush. THANK YOU THANK YOU THANK YOU.”
At previous stops on her reputation tour Swift has brought out surprise guests like Niall Horan, Selena Gomez and Troye Sivan.
Check out fan-shot video clips of Swift and Williams performing “Angels” below: