Grimes reveals she's had a second child with Elon Musk

After welcoming their first child, a son named X Æ A-XII, in May 2020, Grimes has revealed in a new Vanity Fair interview that they secretly welcomed a second child in December through a surrogate, this time a daughter named Y, whose full name is Exa Dark Sideræl Musk.

In the piece, Devin Gordon writes of Grimes' daughter's name: "Exa is a reference to the supercomputing term exaFLOPS (the ability to perform 1 quintillion floating-point operations per second). Dark, meanwhile, is “the unknown. People fear it but truly it’s the absence of photons. Dark matter is the beautiful mystery of our universe.” She texts me a voice memo with the pronunciation of Sideræl—“sigh-deer-ee-el”—which she calls “a more elven” spelling of sidereal, “the true time of the universe, star time, deep space time, not our relative earth time.” It’s also a nod to her favorite Lord of the Rings character, the powerful Galadriel, who "chooses to abdicate the ring.""

Grimes said of her relationship with Musk, "There’s no real word for it. I would probably refer to him as my boyfriend, but we’re very fluid. 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."

She also revealed that they plan to have more children in the future, "We’ve always wanted at least three or four."

The piece also reveals that Grimes is still working on her Book 1 album, and has 15 songs for it so far, one of which is titled "Marie Antoinette 2077".