In a star-studded cast of actors that rivals that of New Year's Eve, a slew of hot A-list couples escaped to Big Sky, Montana for New Year's. None other than Justin Timberlake and Jessica Biel stole away to the midwest skiing destination with their friends and new flames Bradley Cooper & Zoe Saldana, and Leonardo DiCaprio & his new supermodel girlfriend -- Victoria's Secret angel Erin Heatherton!  Oh, to be a fly on that ski lodge's wall...

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Justin Timberlake and Jessica Biel at the 2010 Met Opera Costume Gala

According to Business Insider, the sixsome stayed at the Yellowstone Club, an exclusive invitation-only ski and golf resort -- and were there at least from Christmas until New Year's Eve. An eyewitness told the site, "Leo and Erin and Bradley and Zoe were all staying together." While both may be new couples, it seems they waste no time with romantic getaways!

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As for Justin and Jessica, the source said that they were staying with Justin's manager, her husband and their two kids. But the whole star-studded group had dinner together at least one night.

"Justin went snowboarding a lot but Jessica seemed more low key. Jess would watch Justin's manager's kids as they went tubing," said the source.

And while Justin and Jessica's engagement rumors are swirling, the snooping source tried to sneak a peek at a ring finger confirmation, but to no avail. "Jessica always had gloves on or had just come off the slopes and wasn't wearing it," said the insider. "But Yellowstone Club staff were whispering that the pair had recently gotten engaged."

Sounds like a pretty dreamy vacation!

What celebrity couple would you love to go on vacation with??

Photos Courtesy of Fame Pictures and Pacific Coast News