When she was 10 years old, actress and former Miss America Vanessa Williams went on a vacation that would alter the course of her life. It was the summer before fifth grade and the New York native joined her friend's family on their trip out to California.

"We ended up staying with a family friend of theirs. They had an older daughter," Williams tells "Oprah's Master Class."

Initially, Williams admired the 18-year-old woman. "[She] was one of the cool girls," she recalls. "She made you want to feel like you were a grown-up."

One night, the teen came into the room where Williams and her friend were sleeping.

"She told me to lie down on the floor. She took my bottoms off and she said, 'Be quiet,'" Williams says. "She went down on me."

At 10 years old, Williams didn't understand what was happening or how she should feel about it. "I had no idea what it was, but I knew it felt good," she says. "I knew it felt good, but [was] also something that was not supposed to be happening."

Feeling conflicted, Williams wanted to speak with her parents about the incident when she returned home. However, when she stepped off the plane, something stopped her.

"I saw my dad's face and his face was gray. And I just found out that his brother had died," Williams says. "That was a family drama. I never really talked to my dad about it. I kind of suppressed it."

As a result, Williams began to act differently than children her age. "It awakens your sexuality at an age where it shouldn't be awakened," she explains. "Had that not happened in my life and had I had an opportunity to have a normal courtship with a boyfriend at 16 or whatever... there wouldn't have been that shame that was always haunting me. It made me more sexually promiscuous and more sexually curious at a younger age than I should have been."

"Oprah's Master Class" airs Sundays at 10 p.m. ET on OWN.