Mariska Hargitay, Taylor Swift, Cara Delevingne Photo

From: Photo Flash: Mariska Hargitay and Cara Delevigne Make Surprise Appearance at Taylor Swift's 1989 Tour

Taylor Swift kicked off her 1989 tour in Philadelphia on Friday night, and she had a surprise for the audience. Her friends Mariska Hargitay and Cara Delevigne joined her on stage as the three sang Swift's recent hit 'Style.' Below, check out Swift's Instagram pics of the special evening!