Yahoo! TV has an extended look at Britney Spears’ new MTV documentary ‘Britney: For the Record’ ahead of its premiere on Sunday night. “Sometimes it can get kind of lonely because you don’t open the gate up that much,” the singer explained. “I never wanted to become one of those prisoner people. You’re guarded, you have to be that way.” Spears added that recorded her new album ‘Circus’ allowed “the fun stuff to start to come” for her. Watch the preview below.