When Tesla CEO Elon Musk lamented the decline of the America’s birthrate in June, he made sure to point out that he was “doing [his] part haha.” That may be true, and even more so than we previously thought—according to an Insider report published Wednesday night, Musk had secret twins last year, bringing the tally of his brood to nine.

Insider reports that Musk welcomed twins on the down low with Neuralink executive Shivon Zilis, the director of operations and special projects at the company,last November, a month before he and Grimes had a baby they kept from the public. The outlet cited court documents, which list Musk as the father of the twins and Zilis and as the mother, filed by the couple in April seeking to change the children’s last name to “Musk” and establish “Zilis” as their middle name. According to the outlet, the petition was approved in early May. The documents had a court stamp and Musk’s signature, according to Insider.

In a separate report published on Thursday, CNN stated it had obtained a docket from a Travis County, Texas court confirming the name change petition filed by Musk and Zilis.

Gizmodo was not able to independently verify Insider and CNN’s claims. We reached out to Tesla, SpaceX, and Neuralink for confirmation and comment on Thursday morning but did not receive a response by the time of publication. Tesla has dissolved its PR department and rarely responds to media requests.

The twins would bring Musk’s total amount of children to nine. He has five kids from his first wife, Justine Wilson: a set of twins named Griffin and Vivian as well as the triplets Kai, Saxon, and Damian. Vivian filed to change her name in June, citing a desire to “no longer be related” to her father. Perhaps Musk’s most famous child is his firstborn boy with Grimes, which they named “X Æ A-12,” prompting confusion around the world over how to pronounce the lad’s name. In December, just a month after welcoming twins with Zilis, Grimes and Musk had another baby via a surrogate. Her name is “Y.”

When it comes to Zilis, the mother of Musk’s newest twins, not much is known about her relationship with the tech billionaire. However, as pointed out by Insider, she has occasionally defended Musk and celebrated his accomplishments on Twitter, her boss’ favorite toy.

In May of 2020, Zilis stood up for Musk after former California Assemblywoman Lorena Gonzalez Fletcher tweeted “F*uck Elon Musk” in response to the Tesla CEO’s threats to leave California after the state’s covid-19 restrictions. Tesla officially moved its headquarters from Palo Alto to Austin last year.

“This makes me sad. No one’s perfect but I’ve never met anyone who goes through more personal pain to fight for an inspiring future for humanity - and has done so tirelessly for decades,” Zilis tweeted on May 11, 2020. “Everyone’s entitled to their opinion but mine is that there’s no one I respect and admire more.”

In 2021, meanwhile, she described a photo Musk tweeted of SpaceX’s Starship as “[h]umanity’s history and future in a single photograph.”

Amid the media implosion over this latest bit of news, the Twitter account of the richest man in the world has remained silent. There are still many hours in the day, though.

Update 7/7/2022, 9:11 a.m. ET: This post has been updated with additional information on Zilis.