OK! Exclusive: Britney's Different Personalities

Just before midnight on Jan. 19, Britney Spears popped open several bottles of champagne inside her Beverly Hills mansion. The occasion? She'd just invited six members of the paparazzi into her home for a party.

The stunned photographers were asked to leave their cameras outside, but otherwise to enjoy themselves. And enjoy themselves they did! The group, accompanied by Brit's friend Sam Lutfi, drank, smoked, ate leftovers from the fridge and laughed for about two hours as Amy Winehouse played in the background.

Then, just as suddenly as it had begun, the party came to a screeching halt. "Britney went into her bedroom and came out in a different pair of jeans and her pink wig," one of the photogs tells OK!. "Her eyes went wide and she was yelling, 'How the f**k did you get in here? Get the f**k out! Sam, get them out! Why are they eating my food? Get them out!'"

Britney's complete 180-degree turn was shocking, even to the most hardened of the paparazzi. "One person walked into that bedroom, someone else walked out," one of the photographers tells OK!. "It was scary."

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