Justin Bieber listens for the screams of fans as he performs live at the O2 World Arena in Berlin, Germany on Saturday (April 2).The 17-year-old musician gave his mom, Pattie, a super special birthday gift. Justin tweeted, “sick show in Berlin…brought @studiomama on stage 2 sing her happy bday but she lit her hair on fire with the candles. lol. I saved her.”Justin actually won TWO Kids Choice