A teary OPRAH WINFREY  insisted to BARBARA WALTERS that she and best friend GAYLE KING are not gay – but an in-depth ENQUIRER investigation has uncovered the REAL truth about their shocking secret life.

Inside sources reveal that behind closed doors the two women live a lesbian lifestyle – sleeping together in the same bed and vowing to love each other unconditionally for the rest of their lives.

Both washed their hands of men years ago, insiders say, with Oprah callously betraying her former fiance Stedman Graham to nurture her relationship with Gayle.

What’s more, sources say the wealthy and powerful talk-show queen has used payoffs, bribes and outright lies to keep America from learning her secrets.

"Oprah and Gayle genuinely love each other," an Oprah family member told The ENQUIRER.

"But they don’t think the rest of the world could ever understand their feelings, so they keep their private life quiet."

Oprah, 56, opened up about her sexuality and her relationship with BFF Gayle, 56, during an interview on ABC’s "A Barbara Walters Special: Oprah, The Next Chapter."

Oprah told Barbara: "I am not a lesbian…I’m not even kind of a lesbian."

But when she tried to explain her feelings for Gayle, Oprah became overwhelmed by emotion, breaking down in tears.

"She is the mother I never had. She is the sister everybody would want. She is the friend that everybody deserves. I don’t know a better person. I don’t know a better person," Oprah said.

The talk-show queen continued: "It’s making me cry because I’m thinking about…how much…I probably have never told her that. Tissue please. I now need tissue. I’ve never told her that."

The weepy display triggered a national firestorm, with some questioning Oprah’s sincerity.

"Why be so emotional? There seems to be a lot more to their relationship than Oprah admitted," said the family member. "Now everyone wonders what’s really going on between them."

The two women met in 1976 when Oprah was hired as a news anchor at WJZ-TV in Baltimore, Md. Gayle was a production assistant there and the two hit it off.

While their careers took separate paths, they remained close.

"In the late ’70s, Oprah and Gayle would call each other long-distance and watch the nighttime soap Dallas together. They still laugh about that," continued the family member.

"Back then their relationship was like every other best friend situation, but after Gayle’s husband left her, their friendship changed.

"It’s as if they became the same person. Their love remains unconditional."