Is this the interview you were referring to PB or was it another one?

1)
http://www.adherents.com/people/ps/Oliver_Stone.html

The sexual depravity that Oliver Stone witnessed his parents engaged in while he was a teenager further illustrates the degree to which his parents were not actively practicing Judaism, Catholicism, or any other religion. Oliver Stone's mother first took him to a nudist colony when he was nine years old (Riordan, page 12). When Oliver was eleven years old, his mother was thirty-one and his father was forty-seven. His father began to have an increasing number of extramarital affairs. Oliver was unaware of this at the time. When Oliver was fourteen or fifteen years old, his mother began taking him to nightclubs. While at Hill School, Oliver's father continued having extramarital affairs and the lifestyle of Oliver's mother's friends became increasingly decadent, as they imbibed in the sexual "revolution" of the 1960s. (Riordan, page 24).

After his parents divorced, Oliver found that his father frequently had prostitutes and call girls visiting at the house when Oliver was there. Often they were visiting socially. Apparently some of these women, if it had been many years since Oliver's father had actually hired them, liked to visit socially because they thought Oliver's father was interesting and funny. When Oliver was fifteen year old, his father arranged for him to lose his virginity with a prostitute (Riordan, page 30). Riordan, page 30:

There is little doubt now that Lou's gesture, though made with good intentions, helped to cripple his son emotionally for quite some time. Part of a boarding school circle that rarely mingled with the opposite sex, Stone was an emotionally underdeveloped teenager, and the experience made a profound impact.

Oliver's mother returned to New York City, where she rented an apartment and Oliver began visiting her often. There was a constant parade of prostitutes and homosexuals in his mother's apartment. Men and women hit on him. He frequently found there was rampant drug use, nudity, and group sex at his mother's apartment. When Oliver first walked into his mother's apartment and found her half-dressed in bed with another man, he was shocked, but his mother was very casual about it. Oliver's friend Roger Kirby, who was with him a the time, recounted (from Riordan, page 31):

...his mother said, 'What's the matter? Haven't you ever seen someone in bed before?' The truth was that I hadn't. Not like that. Oliver's mother had a tendency to be more like a peer than a parent. After his father was gone, she was amazingly candid with him. There was no subject she wouldn't broach. Then, other times, she acted like she wasn't interested."

Oliver Stone's experiences with his parents and sexuality had a strong affect on him, and made it difficult for him to relate to women as peers. From: Riordan, page 32:

[During Oliver's senior year at Hill School, he] felt far too traumatized about sexual attraction to deal with women very well.

Roger Kirby comments: "I don't think Oliver ever dated anybody. He had this circle of people [many of them call girls] whom his mother would make available to him directly or otherwise. But I don't think he could relate to the female equivalent of a Hill person [i.e., somebody of similar social standing who had attended a high school similar to his own], and those were the kind of people he saw. I think the first real relationship he had was with his first wife several years later."

2)
Oliver's Mother Issues
Elizabeth Stone, Oliver's ex-wife, says it's no surprise that he would be angry at his mother, or that he would publish a novel that vents his rage. "The crying of a child who was never comforted," is how she interprets her ex-husband's autobiographical novel.

"Oliver as a boy was very isolated and very, very lonely," she says. "Very early in my marriage, I remember having a long conversation with his mom. She'd led a decadent life as a child of the '60s, very tolerant, and she was extremely blunt about her multiple sex partners. . . . She was sophisticated in the European way."

And here Elizabeth offers up a disturbing revelation of Stone's sexual initiation -- as a teenager -- by his mother...