Duff Mckagan - Duff Mckagan Rattled By Book Signing Heckler

The former Guns N' Roses star, who was one of the last people to talk to the late Nirvana frontman before he took his life in 1994, was promoting his new book It's So Easy: And Other Lies when he was confronted with the foul-mouthed fan.

The heckler asked, "Was Kurt Cobain depressed on the airline? Was he in despair?" among other questions about the flight from Los Angeles to Seattle MCKagan took with Cobain days before the Smells Like Teen Spirit singer killed himself.

He was finally asked to leave the venue by a security guard and MCKagan himself intervened when the man yelled, "Get your hands off me before I knock your a** down, motherf**ker."

Clearly offended, the rocker said, "Get the f**k outta here, motherf**ker!" to raucous cheers from fans.