Uh-oh…Bruce and Demi’s baby girl is in hot water in after a weekend of hobnobbing in the Big Apple.

Scout Willis, a 20-year-old sophomore at Rhode Island’s prestigious Brown University, arrested Monday evening after she was caught drinking a beer in New York’s Union Square and then giving cops a fake ID.

Cops spied Scout — the second of Bruce and Demi’s three daughters — just before 7 p.m. Monday with an open 8-ounce Pakistani beer. She gave the officer a New York ID card with the name Katherine Kelly, but eventually wound up handing over her real California State ID.

She was released without bail early today. Willis was charged with criminal impersonation and breaking the open container law. She is due in Manhattan Criminal Court on July 31.

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