Country superstar trio Rascal Flatts have sung with Reba McEntire, Brian McKnight, India.Arie and Natasha Bedingfield, among several other big names in music. But it's their latest collaboration that is arguably scoring the them the most brownie points ... especially from their families. The guys recently announced they are recording a duet with teen heartthrob, Justin Bieber, for Justin's next record. That news has gotten lead singer Gary LeVox a lot of high-fives at home.

"They are fired up!" Gary tells The Boot of the reaction his two daughters, 10-year-old Brittany and 6-year-old Brooklyn, had when he shared the good news. "Brittany says, 'My dad's doing a duet with Justin Bieber, and I DO have Bieber fever!'"

The proud father admits that his daughters aren't quite aware of the magnitude of Rascal Flatts' success over the past decade. "My kids think the only thing I've done is 'Cars,' the 'Hannah Montana' movie, and now the duet with Justin Bieber. I've done three things in ten years!"

The proud dad, who says his kids can "sing their brains out," is looking forward to spending the holidays with his family. "My wife and I, and my girls, always do Christmas Eve at my mom's house. Everybody opens up a gift," Gary says. "Christmas Day, we're just going to be in our own home, watching the reaction of two girls with Bieber fever. It's great to relive your childhood through your kids."

Gary will have a few weeks to spend with his family before the Flatts guys hit the road on January 14 to continue the 2011 leg of their Nothing Like This tour, taking along Luke Bryan and Chris Young as their opening acts. No word yet if Gary will let his girls take a little field trip to the studio with him when Justin comes to Nashville to record the duet.