MADRID, SPAIN - MAY 1: US tennis player Serena Williams (R) and Danish Caroline Wozniacki (L) take a selfie during a charity event held on the ocassion of the Mutua Madrid Open tennis tournament in Madrid, Spain, 01 May 2015. The Mutua Madrid Open takes place at the Caja Magica pavilion in Madrid from 01 to 10 May 2015. (Photo by Evrim Aydin/Anadolu Agency/Getty Images)
