Alex Gurley Alex Gurley is a contributing writer at PEOPLE. She has been working at PEOPLE since 2022. Her work has previously appeared in Just Jared and Buzzfeed. Dia Dipasupil/WireImage In April 2018, Musk sparked dating rumors with musician Grimes (née Claire Boucher) after they shared a flirty interaction on Twitter. Just a few days later, the couple made their red carpet debut at the Met Gala. "They've been seeing each other but have been keeping their relationship under the radar," a source said. In August 2018, the couple reportedly unfollowed each other on social media, leading to speculation that they had broken up. Despite the split rumors, Musk and Grimes were spotted in October at a pumpkin patch in L.A. with his children. In December 2019, Kim Kardashian included the pair in a group photo from the Kardashian-Jenner family Christmas party. In January 2020, Grimes announced her pregnancy and confirmed that Musk was the baby's father. ​​"It's sacrificing your body and your freedom. It's a pretty crazy sacrifice and only half of the population has to do it," she said in an interview. "It was really profound to me when I decided I was going to do it, to actually go through the act of unprotected sex. ... I do actually just really love my boyfriend. So I was like, 'You know, sure.' " In May 2020, Musk and Grimes welcomed their first baby together, a son named X Æ A-12, or X for short. Musk shared that Grimes had taken on the majority of parenting duties in the first few months, but he looked forward to being able to be more involved when X was older. The couple made a joint appearance on Saturday Night Live in May 2021; though they had "semi-separated" by September of that same year. "It's mostly that my work at SpaceX and Tesla requires me to be primarily in Texas or traveling overseas and her work is primarily in L.A.," he told the New York Post's Page Six. "She's staying with me now and Baby X is in the adjacent room." Despite their separation, the couple welcomed their second baby via surrogate in December 2021. Grimes confirmed the birth during an interview with Vanity Fair in March 2022, sharing that they welcomed a baby girl named Exa "Y" Dark Sideræl. She also shared that she and Musk were back together. "There's no real word for it. I would probably refer to him as my boyfriend, but we're very fluid," she said. "We live in separate houses. We're best friends. We see each other all the time. ... We just have our own thing going on, and I don't expect other people to understand it." On the same day Vanity Fair published the story, Grimes shared that the couple's relationship status had changed since the interview. "Me and E have broken up *again* since the writing of this article," she tweeted. "But he's my best friend and the love of my life, and my life and art are forever dedicated to The Mission now, I think Devin [Gordon of Vanity Fair] wrote that part of the story rly well. Sique - peace out." In September 2023, journalist Walter Isaacson's biography about Musk revealed that the entrepreneur and Grimes had secretly welcomed a third child — son Techno Mechanicus, who also goes by “Tau." Shivon Zilis