Almost exactly a year after her sister Kate Middleton's royal wedding, Pippa Middleton is stealing the scene again -- but it's nothing as light-hearted as flirty chats with Prince Harry or a derriere-enhancing bridesmaids' dress.

After partying at a raucous, raunchy bash in Paris until 5 a.m., the socialite, 28, took a spin with three pals in a convertible on Saturday when photographers snapped the foursome -- and, in a bizarre turn of events, the driver of the car took out what appeared to be a semi-automatic pistol and aimed it at the photographer. Sitting in the passenger seat, Middleton laughed.

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Nobody's laughing now. As revealed in the new Us Weekly, Middleton will be questioned by French authorities about the gun-waving incident and faces nearly $6000 in fines and even jail time if convicted.

The royal in-laws are not pleased. "This is embarrassing for them," a royal source says. Including big sister Duchess Kate, 30. Her sibling's surprising photo "has put Kate in a very difficult position," the source adds.

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The mystery man pointing the gun in question, meanwhile, has finally been identified: He's Romain Rabillard, a 36-year-old French attorney, who ironically represents German firearms manufacturer Heckler & Koch. The single Rabillard parties with a crowd of chic Parisians, including wealthy clothing designer Viscount Arthur de Soultrait -- Middleton's pal, whose wild 30th birthday bash she attended Friday evening.

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For much more on Pippa's shocking new scandal -- how the royals and the Middleton family is reacting and how Pippa is dealing with the crisis -- pick up the new Us Weekly, on stands Friday.

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