Best Friends Forever?(A One Direction Fanfic)

Ever since they were chasing eachother around on the playground it had always been Harry and Payton. They were brother and sister- according to what they told people. At age 16 when their friendship was still strong, they both decided to try out for X-Factor. But when Harry gets put in a group with 4 other guys, will their friendship ever be the same? Will it fall apart or blossom?