On Tuesday night, fans got a huge surprise during Taylor Swift's concert at the Staples Center in L.A. -- Justin Bieber made an appearance! "Who wants to see my friend Justin?" Taylor asked, before inviting Justin onstage with her and performing "Baby" with him. READ IT: Justin Bieber: Never Say Never Director's Fan Cut out now
This isn't the first time Taylor has sang "Baby" during her Speak Now tour -- she paid tribute to her famous friend Canada and performed the song at her show in Toronto. Watch Justin's and Taylor perform "Baby" below.
"@Taylorswift13 has been there from day one. True friend. #goodtimes," Justin Tweeted afterward.
Photos: Courtesy of Sirius XM; Dave Allocca/Startraks Photos