Sofia Vergara and Joe Manganiello spent their New Year's Eve in Las Vegas, where they caught a performance of Britney Spears's "Piece of Me" show at Planet Hollywood. They were joined by Ar**ld Schwarzenegger and his girlfriend Heather Milligan in the audience. Sofia and Joe, who got engaged on Christmas Day, recently returned from a Hawaiian getaway to celebrate Joe's 38th birthday. It was an exciting 2014 for the couple and it looks like 2015 might have even more in store!