Elon Musk and Grimes share three children, not two as previously believed, according to a new biography about the Tesla CEO.
In addition to being parents to son X Æ A-12, 3, and daughter Exa Dark Sideræl, 20 months, the on-again, off-again couple at one point welcomed a child named Techno Mechanicus, nicknamed Tau, the New York Times noted in a Sept. 9 review of Walter Isaacson's book Elon Musk, set to be released Sept. 12.
E! News has reached out to Musk and Grimes' reps for comment and has not heard back.
The SpaceX CEO, 52 and now a father of 11, and the musician, 35, have dated on and off since 2018 and welcomed their daughter, nicknamed Y, via surrogate. Grimes had revealed her existence in a 2022 Vanity Fair interview, adding that she and Musk have "always wanted at least three or four" children.
Grimes also told the magazine that the two were living in separate houses and were "best friends." She later tweeted, "Me and E have broken up *again* since the writing of this article haha, but he's my best friend and the love of my life, and my life and art are forever dedicated to The Mission now."
Musk also shares 19-month-old twins Strider and Azure with Shivon Zilis, an executive at Neuralink, one of the companies he co-founded. Their names were first revealed publicly in a Sept. 6 Time magazine cover story adapted from Isaacson's upcoming biography.
"He really wants smart people to have kids," Zilis is quoted as saying about Musk, who offered to be her sperm donor so that, Isaacson adds, "the kids would be genetically his," according to the recent New York Times review of the book.
Before starting a family with Grimes and Zilis, Musk previously welcomed six children, including twins, with ex-wife Justine Musk.
See Musk's complicated family tree below: