It's often easy to forget that Justin Bieber is just 16 years old.
After all, the guy is a music mogul, future movie star, author and, simply put, one of the most fascinating people on the planet.
But he's still prone to fits of giggling, just like the rest of us. During a concert in Pittsburgh this week, Justin was forced to stop singing on two separate occasions because he was overcome by laughter. The cause of such guffawing? Two girls in the crowd fighting over his shirt.
Watch the adorable action now: