h-oh! Watch yourself, Justin Bieber! The ‘What Do You Mean?’ singer marked his live return with a skateboard fail — hurting his leg on stage in the process. Poor guy. Click to WATCH!Careful, you’ve got a tour and new record to promote!Justin Bieber, 21, who isnormally an expert on a skateboard, showed he’s prone to hurting himself just like any other boarder when he injured his leg trying to perform a trick at his Nov. 13 concert event.