Taylor Swift is in London, England this weekend for a three-night Eras Tour run at Wembley Stadium. For her second night on Saturday, she treated fans to the live debut of “Thank You, Aimee,” and performed “Castles Crumbling” with her tour mate, Paramore’s Hayley Williams.

During her performance of The Tortured Poets Department: The Anthology track “Thank You, Aimee,” which she played on acoustic guitar, she folded in parts of “Mean.” The songs about bullies made for a complementary mashup, as fan video highlights. She also changed the “Mean” lyric “Someday I’ll be living in a big old city” to “Someday I’ll be singing this song at Wembley,” which elicited audience cheers.

For the second surprise song, Swift performed Speak Now (Taylor’s Version) from the vault track “Castles Crumbling” featuring Paramore’s Hayley Williams, who joined Swift for the piano-led song (Paramore serves as the opening guest for the Eras Tour European leg). Partway through as fan footage showcases, Swift told Williams, “I love you so much. You’re so good, it’s crazy. I cannot believe that I get to be on a tour with Hayley. I can’t believe she’s ever talked to my once.” Williams responded with a laugh and said, “You’re my longest music friend. Thank you. I love you.”

Last weekend, Swift premiered “Carolina” live as part of a mashup with Evermore’s “No Body, No Crime” along with “The Manuscript” during her third and final Eras Tour stop in Liverpool, England at Anfield stadium. She has premiered a number of songs live during her surprise acoustic sets, including recent debuts of “The Bolter” and “Crazier” while in Edinburgh, Scotland; “The Tortured Poets Department” and “Fresh Out the Slammer” in Lisbon; and “How Did It End?” in Stockholm, Sweden.

On Friday, during the opening Eras Tour London concert date, Swift performed “The Black Dog” live for the first time. Her final Eras Tour show in London is on Sunday. Next weekend, she heads to Dublin, Ireland. The European and U.K. leg of the tour runs through August, before heading to Canada for a string of dates that conclude on Dec. 8 at BC Place in Vancouver. Swift recently announced that she will be wrapping the Eras Tour for good at the end of 2024.