After this shock, fans can’t stop laughing.

Taylor Swift When she surprised fans with a surprise appearance, it made all their wildest fantasies come true. HAIM‘s sold-out July 21 show in London—and lucky for viewers, plenty of footage has surfaced on the Internet to relive this moment forever.

As @vixeth shared a TikTok clip, HAIM rocked out to their song “Gasoline” but, halfway through the track the group stopped to greet Taylor, who is featured in “Bad Blood”. Taylor and the HAIM siblings performed an edgy mashup rendition of “Gasoline” as well as Taylor’s famous solo song, “Love Story”. More footage is available here. here.

Taylor, who was on stage at the concert, stated that Taylor and his idea to work together during the concert was part a masterplan for getting the crowd to “sing the loudest they have ever sung”

She added, “Which is a big challenge because you have been singing very loudly—extraordinary work.”