From Wiki:

• Trace Cyrus’ sister, Miley, and father, Billy Ray, appeared in the song’s video, which was shot near Santa Clarita, California. Trace Cyrus told MTV News: “We kind of based it on the story of The Lost Boys. We just took the vampires out of it. Just the whole carnival idea of, like, kids coming together. They come in and take over this park, and we’re gonna perform for them. There’s definitely going to be some stunt guys here who are going to be doing jumps and stuff. It’s gonna be wild.”
• Cyrus told Kerrang! magazine April 18, 2009 that though a lot of people think this song is about being a kid forever, “it’s actually about wanting to be in a relationship with a girl who’s underage so bad and how age limitations don’t let you do that. We like to shock people.”

“Seventeen Forever” by Metro Station