English pop singer Ed Sheeran joined Taylor Swift on stage during the acoustic segment of her Eras Tour at Wembley Stadium in London on Thursday, shows a video dropped by the official X handle of The Eras Tour.

During Swift's performance of the song Everything Has Changed, she paused and joked that something didn’t feel quite right. Soon Ed Sheeran appeared, joining the former on stage for an impromptu collaboration.

Together, they performed a mashup of three songs — End Game, Everything Has Changed and Thinking Out Loud.

Both End Game and Everything Has Changed are duets Swift and Sheeran sang on Swift’s past albums Reputation (2017) and Red (2012). Thinking Out Loud from Sheeran's X album is one of his biggest hits and earned him a Grammy for Song of the Year in 2016.

During their performance, Swift paused to give a speech, formally welcoming Ed Sheeran. She said, “This is one of my best friends in the world, to the point where I feel like he’s a second brother of mine. We toured together on the Red Tour. Every time I am doing the ‘Red’ part of this show, I think about the memories that we’ve made. And now he is someone who plays at Wembley, like, every week.”

She further said, “This is like regular for him. And he works so hard, and he’s on tour right now, and he’s probably so tired. But he wanted to come and play for you and do this for all of us, so give it up for Ed Sheeran."

Earlier this month, Taylor Swift's Vienna concerts were cancelled following intelligence input on alleged plotting for a terror attack at the venue.

During the European leg of the ongoing Eras Tour, the singer has so far performed in France, Sweden, Portugal, Spain, Scotland, Netherlands, Switzerland, Italy, Germany and Poland.

At the 100th show of the Eras Tour in England’s Liverpool, the 34-year-old pop singer announced the official end of the concert in December in Vancouver, Canada.