R. Kelly accuser describes trying to get the singer to destroy sex tapes he made of her when she was 17

• An R. Kelly accuser testified about how she tried to get him to destroy sex tapes he made against her will.
• She said her 6-month sexual relationship with the R&B singer, when she was 17, was the worst period of her life.
• Kelly once said it was OK for him to like young women because he was a "genius," she testified.

A woman who testified in R. Kelly's sex crimes trial Thursday said she tried and failed to convince the singer to destroy sex tapes he made of them.

The woman, who was identified as only "Stephanie" in court, said she had a sexual relationship with R. Kelly in 1999 when she was 17 years old.

She said Kelly took videos of them having sex even when she didn't want him to and described the six months of their relationship as the lowest point in her life.

"I have never been threatened that way before or since," Stephanie said through tears. "He humiliated me. He degraded me. He scared me. I will never forget the way he treated me."

Other accusers said Kelly obsessively took videos of sex he had with women. One woman who testified earlier this week said he kept up to six iPads in a backpack that he or a member of his entourage carried around everywhere to record every sexual encounter.

For his current trial in a federal court in Brooklyn, prosecutors have accused Kelly of running a criminal enterprise where he directed other people to recruit women for sex, and that he sexually abused those women and produced pornography for those experiences. He has pleaded not guilty to all the charges against him. Kelly - whose real name is Robert Sylvester Kelly - was also tried on child pornography charges in 2008 and acquitted at trial.

Kelly said he liked younger women and said it was OK because he was a 'genius'

Stephanie said a member of Kelly's entourage first approached her at the "Rock 'n' Roll McDonalds a year earlier, when she was 16 years old, and gave her Kelly's number. A studio manager for Kelly testified earlier Thursday that Kelly often instructed his employees to give his phone number to women the singer was interested in.

The teenager "wasn't interested," she said, and threw the number out at the time. But she met Kelly in person a year later, when he had an event around the corner from a hotel coffee shop where she worked as a barista. She testified that she wanted to ask him whether he'd meet with a close friend of hers, who was an aspiring singer.

Stephanie said she entered into a relationship with Kelly after having already suffered sexual abuse.

"That was definitely the worst part of my life," she said. "I had low self-esteem. I had already suffered sexual abuse from a member of my family, from my boss, from men on the street. I was vulnerable."

She said her experiences with Kelly were degrading. He "orchestrated the sounds" she made and forced her to perform sex acts in front of other people, she said. He would sometimes leave in the middle of sex and required her to remain in the same pose for hours until he returned, erupting if her body shifted, she testified.

During one dinner with two rappers named "Boo" and "Gotti" - apparently the hip-hop duo who collaborated with Kelly and Jay-Z on the 2001 single "Fiesta" - Kelly said he liked "young girls," Stephanie said. Kelly compared himself to Jerry Lee Lewis, the famed singer-songwriter whose career cratered once he married his 13-year-old cousin.

"He mentioned that he likes young girls and that people make such a big deal of it," Stephanie said, before quoting Kelly: "'Look at Jerry Lee lewis. He's a genius and I'm a genius. We should be allowed to do whatever we want. Look at what we give the world.'"

Stephanie testified that she tried to leave Kelly in the fall of 1999, after a particularly degrading sexual experience. But she felt restrained by the sex tapes Kelly kept, she said.

She met with him multiple times in person and proposed destroying the tapes, but he was noncommittal, she said.

She finally cut off contact after a phone call where, when she asked once again to destroy the tapes, he asked her to come over to his studio. Stephanie said she believed he just wanted more sex.

"It was then I knew he didn't have any intention of destroying the tapes," she said.

It was the final time she spoke with him, she testified.

"I felt used and humiliated and degraded," she said. "I didn't want to feel abused anymore."

Stephanie was accompanied in the courtroom by Gloria Allred, her lawyer. Nicole Blank Becker, one of Kelly's lawyers, who cross-examined Stephanie, addressed Allred's presence in the courtroom. She asked whether Allred might represent her in a civil lawsuit against Kelly, where she may stand to be awarded monetary damages. The accuser testified she hadn't talked about filing a civil lawsuit and did not plan to.

Stephanie said she has never spoken publicly about her experience and never planned to again.