Carly Simon had her first sexual experience when she was just seven years old.
The 70-year-old singer admits the "heinous" encounter with a teenage boy, who was a family friend, effected her view on sex for a long time afterwards.
She said: "It was heinous. It changed my view about sex for a long time."
The 'You're So Vain' hitmaker confided in her sisters, who told her mother, leaving her "devastated" when the unnamed guy was subsequently banned from their household.
She recalled to People magazine: "I was devastated because I thought I was in a romance. Which I think happens to a lot of girls. Your libido overpowers everything! You're so libidinous even at the age of nine and 10. And sometimes there's an outlet there.
"I bet many more cases than we know about there is."
And the veteran singer even kept the encounters secret from a child psychologist because she says she wanted them to continue.
She said: "Even when [psychologist] Dr. Frunzhaufer thought that he could get to the bottom of it with 'Twinkle twinkle little star,' I didn't want to tell him. I said, 'Yes he touched me on the chair. I was happy!' "
Though she confided in her sisters, Carly doesn't think they believed her until they read an advance copy of her forthcoming autobiography 'Boys in the Trees'.
She said: "Neither of them were at all aware of what had happened to me. I told them the first year that it was happening, and they thought I was just trying to be one of the bigger girls."
Love to you RT @Blondi_SOS: Ordered @CarlySimonHQ autobiography today, on sale in the UK 3 December. pic.twitter.com/1OK7YmggHd