Justin Bieber: Fan dates are fun

Justin Bieber says having fan dates is "as fun for [him] as it is for her".

The Canadian superstar was accompanied to Sunday's Billboard Music Awards by Virginia teenager Cady Eimer.

The fan originally asked Justin to be her prom date, but the teenage heartthrob had to turn down the offer because of work commitments, so he hatched another plan with manager Scooter Braun.

"At the end of the day, it's as fun for me as it is for her. I'm able to hang out and have a good time. I couldn't go to prom, so why not have her come and hang out and have a good time," he told ET Online.

"It was mine and Scooter's idea. We were like, 'We can't make it to the prom, but what's coming up soon that she would want to come to?' So we were like, 'Billboard Awards!'"

Cady was thrilled to be part of Justin's experience at the prestigious music ceremony at the weekend. She gushed about the once-in-a-lifetime event.

"I asked him to prom last year... and he couldn't make it. Yesterday at my prom, I'm standing there and a video turns on and he was like, 'I can't make it but I have a car for you to come to the Billboard Awards,' and here I am!" she exclaimed.

Justin scooped the Top Social Artist at the Billboard Music Awards. The 18-year-old star explained how he feels when he's honoured with such accolades.

"I don't ever expect it," he said. "So, every time it's always a surprise and...I never know what to say. So, going up [on stage], it's always coming from the heart and everything that I'm really feeling, I just say."

Meanwhile, Justin announced the launch of his Believe tour on The Ellen DeGeneres show. The star gave every studio audience member two tickets to see one of his performances.