Kelly Osbourne has recounted receiving her first line of cocaine from a friend of her father, Ozzy Osbourne, during her youth.

In the new documentary If These Walls Could Rock, Osbourne, 41, detailed her experiences growing up at the Sunset Marquis hotel in Los Angeles. The hotel became a site for her early explorations, she said.

"I had my first drink in this hotel. I had my first kiss in this hotel. I did my first line of cocaine in this hotel… which was given to me by one of my dad’s friends in a very, very, very big band, and I could never tell my parents because they would f****** kill him," Osbourne recalled.

Her mother, Sharon Osbourne, explained that the family would stay at the hotel during Ozzy's U.S. tours before they settled in Los Angeles. Sharon noted that Ozzy enjoyed the hotel's atmosphere, which allowed him to maintain a "sex, drugs and rock 'n' roll" lifestyle.

"He would love it here because he could wander," Sharon said. "He’d get to know other guests at the hotel, making it feel like 'you were in your own home with a lot of friends'."

Kelly described the Sunset Marquis as the only hotel where her father could feel at ease. "We’d be kicked out of everywhere, but not the Sunset Marquis. My dad could misbehave politely here."

ZZ Top guitarist Billy Gibbons also shared a memory of Ozzy at the hotel, recounting an incident where Ozzy, by the pool, initiated a glass-smashing spree that led to a prolonged party. "Within 30 seconds, every glass that had been surrounding the pool was now in shatters," Gibbons said. "And it became so dangerous that nobody could leave, so the party went on until the wee hours. That’s the kind of s*** that happens at the Marquis."