Last night, for Coachella Weekend 1, Calvin Harris took the stage to play some of his biggest hits. Yes, his girlfriend Taylor Swift was there, and many thought she would be Harris's surprise guest because that's exactly what was being teased for his set: "a surprise guest." But it wasn't Swift. It was Rihanna

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We knew RiRi was there . . . She was photographed chillin' with Leonardo DiCaprio. But most people assumed she was there just for fun, not for business. Good thing for the Coachella crowd she did, though, because she and Harris reunited for a raging rendition of their 2012 “We Found Love” track on the Main Stage. 

Check out the full set above, and here's Swift (below) singing along with her squad member Lorde

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I'll NEVER forget this moment. @badgalriri @calvinharris #coachella

A video posted by Taylor Swift (@taylorswift) on