SISTAR heated up the stage with "So Cool" on '2011 KBS Music Festival' with their special dance performance and their live vocal abilities. However, what caught netizens' eyes were their sexy red dresses. Their dresses featured nude-colored panels around the top and chest, giving it the illusion that they were showing more skin than they actually were. The short length of their dresses also made it more risqué. During parts of their choreography that required the girls to bend over, Hyorin ended up showing a bit more than she probably bargained for, leaving viewers quite shocked. Netizens wrote, "It seems they need to pay a little more attention to their outfits," "I was so surprised during that part," "I was worried from the start and then it happened." Source: Money Today via Nate