LONDON, ENGLAND - JUNE 27: Taylor Swift and Serena Williams perform onstage during The 1989 World Tour at Hyde Park on June 27, 2015 in London, England. (Photo by Brian Rasic/LP5/Getty Images for TAS)
LONDON, ENGLAND - JUNE 27: Taylor Swift and Serena Williams perform onstage during The 1989 World Tour at Hyde Park on June 27, 2015 in London, England. (Photo by Brian Rasic/LP5/Getty Images for TAS)