"I was in bed and Cher got up to go to the bathroom and get ready for bed.
I watched her take off her clothes. There was a woman's naked body.
I remember thinking, 'This is not
bad, lying next to this beautiful lady.'"
The singer - who lost his virginity to his dad's girlfriend at the tender age of 12 - also admitted he used Sonny Bono's address to get into the school with the best looking girls.
The heartthrob star says Cher's former husband gave him permission to use the fake address after he had set his heart on the Los Angeles school.
He said: "Everywhere I looked there were these hot little 13-year-olds.
I said, 'Whatever it takes, I want to go here.' Sonny was fine with the deception so I enrolled."
Meanwhile, Anthony says his dad introduced him to drugs at the age of four.
He revealed: "We were walking down Sunset Strip, and he gently blew some pot smoke into my face."