Octuplets mother Nadya Suleman says she didn't tell her sperm donor she was having more children after the first six, and fears his resentment for the betrayal.

In a video shot in a fondue restaurant and posted to the RadarOnline Web site Thursday, Suleman says she used frozen fertilized embryos left over from her first conceptions to become pregnant with eight additional children. The donor didn't know she had the leftover embryos, she said.

"I went behind his back and used them all," she says. "He didn't want me to. I feel so much guilt for that."

The videographer, identified by Radar as Suleman's best friend, says at one point that the sperm donor has a wife and family. But Suleman warns her away from giving away too much about the man, adding that "he'd lose everything he's created in his own life" if his identity was revealed.

Suleman says her older children are increasingly curious about who their biological father is. She refuses to identify him, saying she wants to protect his privacy, but also wants him "to somehow, privately, secretly know (the children) in a controlled manner."

Dipping cheesecake into melted chocolate, Suleman confesses in the video to making some mistakes.

"I screwed myself. I screwed up my life, I screwed up my kids' lives," she says. "I have to put on this strong facade and I have to pretend like I don't regret it."

Suleman gave birth to the world's longest-surviving set of octuplets on Jan. 26.

PHOTOS: Click here to see photos of "Octomom" and her kids.