Justin Bieber - Justin Bieber Takes High School Student To Awards Show

Cady Eimer, 18, from Virginia, has spent months campaigning to have Bieber join her for her high school prom, and during the event on Saturday night (19May12), he surprised her by sending a video message inviting her to glitzy prizegiving in Sin City.

Bieber said in the message, "I know you wanted me to be at your prom, but I'm actually going to be at the Billboard Awards, but I'll have a car waiting for you so you can come to the Billboard Awards with me tomorrow... Cady, I love you thank you for your support and I can't wait for you and your sister to be my guests at the Billboard Awards."

Footage from the prom shows Eimer staring open-mouthed at the screen before screaming and hugging her friends.

She was taken to Las Vegas the following morning along with her sister to join Bieber at the ceremony and afterwards she thanked the pop star for the special trip, writing in a post on Twitter.com, "Justin Bieber... thank you so much for an amazing night! I had the time of my life... Not gonna lie, I'm sad today's over. It was so much fun."

Bieber told People.com, "I couldn't make it (to the prom) so I said I need you to fly to the Billboard Awards and you can be my date. She's a big fan and I thought it would be fun."

However, the singer did forget one important detail, adding, "I didn't get her a corsage."