Elon Musk Has Been "Very Immature" On Twitter, Says Grimes Elon Musk Has Been "Very Immature" On Twitter, Says Grimes Grimes received a critical comment from a TikTok user questioning her love life Elon Musk and Grimes began dating in 2018 (AFP Photo) Grimes conceded that her partner Elon Musk has been "very immature on Twitter" at times while defending the Tesla CEO from critics. The Canadian singer-songwriter came to Elon Musk's defense after a TikTok user accused the Tesla CEO of "destroying the planet and humanity" while another asked if he was a "Men's rights activist". Grimes and Elon Musk began dating in 2018 and welcomed their first child together in May last year.