After Elon Musk took his son X Æ A-Xii to the Oval Office, his ex-partner and the child's mother, Grimes, said the four-year-old "shouldn't be in public like this". "I didn't see this...thank you for alerting me. But I'm glad he was polite," Grimes added while responding to a social media user. Earlier, X joined Musk at Donald Trump's rally.