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Britney Spears may be the queen of 2015 already.

The pop star rang in the new year during her Las Vegas show, surrounded by a slew of A-listers.

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Miley Cyrus and Patrick Schwarzenegger cozied up with his father Arnold Schwarzenegger looking on. Meanwhile, newly engaged Joe Manganiello and Sofia Vergara also rang in the new year with the "I'm A Slave For You" singer. Iggy Azalea? She was there, too.

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Before the show Iggy tweeted, "Oh and lasssstttttt thing.... I'm going to see Britney spears in show tonight!!!!!!!!!!"

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Miley, however, may have been more excited. Sitting on the front row, the controversial singer sang along with Britney and spoke to her during the songs, encouraging her buddy during her 90-minute "Piece of Me" show. Patrick, meanwhile, filmed video and took pictures from his phone.

With all of these celebrities in the house, how would Britney end up ringing in the new year? With her boyfriend Charlie Ebersol and a little hot chocolate.

In a Twitter video, the couple wishes everyone a happy new year as they clink together coffee mugs. She captioned the video, "Hot chocolate beats champagne everyday! Happy new year everyone. May your year be blessed with joy!"