R. Kelly began grooming a teen to be one of his sex “pets” when she was 14 years old, his former girlfriend claims in a new interview — the latest disturbing sexual misconduct allegations against the R&B star.

Kitti Jones, who dated Kelly from 2011 to 2013, says in a new BBC Three documentary that Kelly made her have sex with him and others inside what she characterized as a “sex dungeon.”

Jones detailed an alleged incident where she was introduced to another woman who she claims was supposed to show her what Kelly likes sexually.

“He proceeded to tell me, you know, to undress, and then I sat in the chair and he started recording me,” Jones told reporter Ben Zand. “He would record everything that we did at this point.

“That’s when the girl walked in,” Jones continued. “He had her crawl on the floor toward me and perform oral sex on me. And he said, ‘This is my f — king pet. I trained her. She’s going to teach you how to be with me.’”

Jones noted that some of the girls in the “sex dungeon” appeared to be underage, and says Kelly informed her he’d been grooming a girl since she was just 14.

A friend of Kelly, meanwhile, said in the documentary that Kelly’s interest in young girls was “common knowledge” and that the singer pressed him to seek out girls who “looked young” for him.

“How do you defend yourself against someone who’s been honing their skills as a predator for 25 years, who’s also a multimillionaire, and one of the most famous and successful artists in the music industry?” Lovell Jones, a former collaborator of Kelly, says in the documentary.

A rep for R. Kelly said the singer does not have a comment on the new allegations.

The documentary, which was set to air Wednesday in the United Kingdom, comes eight months after Kelly was accused of leading a sex-fueled “cult” at his home by the parents of his live-in girlfriend, Joycelyn Savage, in an article published by BuzzFeed.

Savage later denied that she was being manipulated to stay there against her will, while Kelly denied the “cult” allegations against him through a representative.

Jones also spoke out in that BuzzFeed report, claiming Kelly controlled aspects of her life such as phone use and social media while she lived with him.