A male porno star by the name of JULIAN ST. JOX told the "Star" that he and his mattress actress girlfriend swung with KIM KARDASHIAN and a female porn minx back in September of 2001. It happened at a swingers' party at the Wyndham Hotel in Culver City, California. Julian says Kim showed up with a "black male."

Now, Kim was married to music producer DAMON THOMAS at the time . . . but we don't know if he was the "black male" in question. Anyway, Julian says that his date, mattress actress EMILY ANN, propositioned Kim, which led to some GRINDING on the dance floor.
Eventually, the four of them were in a private room, and Kim was RECEIVING ORAL SEX from Emily. Then Julian joined in and they began rolling around in a sweaty ball of teeth, limbs and hair. Then the couples SWAPPED. Emily went at it with Kim's man, and Julian got down to business with Kim. He says, quote, "I gave Kim oral sex, I kissed her all over her body and we had sex in a few different positions." He adds, quote, "She looked like she was enjoying herself very much. She was a little submissive, but she was good. She knew what she was doing. She was very responsive to me."
A Kardashian rep is denying this, but the "Star" says it confirmed the story through another source . . . if that means anything to you.