How a mother of Elon Musk’s children became a key witness in his lawsuit against OpenAI

Shivon Zilis walks outside a federal courthouse in Oakland, California, on May 6, 2026. Her testimony this week shed light on her role in the flow of information between Elon Musk and OpenAI. (Manuel Orbegozo/Reuters via CNN Newsource)

Shivon Zilis was an under-the-radar executive at Elon Musk’s companies and an OpenAI board member back in 2022. But she was hiding a major secret – Musk was the father of her twins born the year before.

Now, her ties to the Tesla CEO have put her at the center of a courtroom battle between the world’s richest man and the company credited with kicking off the AI boom.

Zilis’ testimony on Wednesday shed light on the fundamental role she played in the flow of information between Musk and OpenAI during critical time periods. She effectively served as a conduit between Musk and OpenAI’s leaders until Musk started his own AI company in 2023, evidence presented in court this week indicated.

Musk, who co-founded and funded OpenAI, sued the company and its leaders saying they deceived him, breached a charitable trust and unjustly enriched themselves when the company expanded from a nonprofit mission to a profit-oriented structure. Zilis was initially a co-plaintiff in the case, though she dropped off at her request before the trial began.

OpenAI has denied Musk’s claims, saying he at different times pushed to create a for-profit subsidiary. The company also alleges Musk sued the company because he couldn’t gain full control of it, Musk left OpenAI in 2018 and now owns a rival AI company, xAI.

OpenAI alleged that while serving on OpenAI’s board, Zilis knew Musk planned to launch a competitor before it was public knowledge.

In text messages to a friend, Zilis wrote she had to resign from the board because Musk’s “effort has become well known.”

“When the father of your babies starts a competitive effort and will recruit out of OpenAI, there is nothing to be done,” Zilis wrote at the time in the messages entered as evidence.

Zilis was instrumental in Musk’s dealings with OpenAI from the company’s early years, including discussions in 2017 about the potential formation of a for-profit structure to fund AI development. She discussed possible solutions to OpenAI’s funding concerns with the company’s leadership, Musk and his senior advisors, in emails, messages and meeting notes submitted as evidence. Some of the options included developing a for-profit corporation or having Tesla absorb OpenAI.

OpenAI attorneys tried to show Zilis and Musk discussed creating a for-profit entity for the AI company. Musk’s attorneys, on the other hand, attempted to prove Zilis also believed OpenAI violated its original nonprofit mission.

Zilis, under questioning from Musk’s attorneys, said that many different possibilities for funding were discussed, including granting Musk having a majority stake in OpenAI. She also said the group never discussed replacing the nonprofit with a for-profit corporation.

After Musk left OpenAI’s board and stopped providing funding, Zilis continued acting as a conduit for Musk.

“Do you prefer I stay close and friendly with OpenAI to keep info flowing or begin to disassociate? Trust game is about to get tricky so any guidance for how to do right by you is appreciated,” Zilis texted Musk in 2018 after he had left the board.

Musk wanted Zilis to stay “close and friendly” and planned to attempt to recruit several OpenAI staffers to Tesla, he replied.

OpenAI president Greg Brockman testified on Monday that Zilis had said her relationship with Musk was “platonic,” so the board allowed her to remain. Brockman added that he was not aware of her personal relationship with Musk until later.

The case could have major ramifications for the AI race if Musk wins and Judge Yvonne Gonzalez Rogers grants the remedies he seeks. That would include forcing OpenAI to revert to a nonprofit structure and revoking Altman and Brockman’s board positions.

Zilis testified that her relationship to Musk did not affect her conduct as a board member, saying she had “an allegiance to the best outcome of AI for humanity.”

As a board member, Zilis had voted in favor of a US$10 billion investment by Microsoft that Musk heavily criticized.

But Zilis testified her views on OpenAI changed after Musk’s criticism of the investment, along with Microsoft CEO Satya Nadella’s involvement in restoring Altman as CEO after he was briefly ousted in 2023.

“It just seemed like everything we’d put together from the nonprofit to just retain the mission to make this good for humanity, just somehow had been ripped out or lost its teeth,” Zilis said.

Zilis was a prominent venture capitalist before meeting Musk, well-versed in the world of AI long before it became the focus of the tech and business world.

Zilis testified she met Musk in 2016 through her early role in OpenAI as an adviser, after which they had a “one-off” romantic encounter. That turned into a friendship and eventually a job, Zilis said. She went on to hold senior roles at Tesla, xAI and Neuralink. Musk, during his testimony, described Zilis as both a senior adviser and “chief of staff.”

Toward the end of 2020, Musk had a different kind of offer: to father her children.

“He in general was encouraging everyone around him to have kids, noticed I had not, and said if that was ever interesting, he would be happy to make a donation,” Zilis said. Their twins were born via IVF in 2021.

No one, not even Zilis’ dad, knew who the father of her children since she signed a confidentiality agreement. Then in 2022, Business Insider broke the news.

Zilis initially described Musk’s role as a donor. But his role evolved into fatherhood, Zilis said, and they had two more children.

Musk called Zilis his “partner” during his testimony last week, and the two live together when travelling, she said this week. He also visits her and the children in Austin, Texas, where she is based.

By Hadas Gold, CNN