Elon Musk and Grimes have welcomed their second child, a baby girl, together.

Surprise! Grimes And Elon Musk Secretly Welcomed A Baby Girl

This is their second child together.

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Grimes and Elon Musk are officially the parents of two children. The Canadian singer, who had a son with the Tesla CEO in 2020, somewhat unintentionally made the revelation during a March 10 interview with Vanity Fair. Even more unexpected than how the publication came to find out about her second kid with Musk is the unique name they gave their baby girl.

The baby girl’s name is Exa Dark Sideræl Musk. Could you guess what her nickname is? It’s simply the letter, “Y.” We should have seen it coming, right?

The on-again, off-again couple, who reportedly began dating in May 2018 and then “semi-separated” in September 2021, welcomed their first child together — a son named X Æ A-12 — in May of 2020. Shortly after their son’s arrival, Grimes told Bloomberg she and Musk had nicknamed their baby “X” for short. Looks like the duo is keeping with unprecedented baby names.

According to Vanity Fair, Grimes and Musk named their daughter Exa after the supercomputing term exaFLOPS. The first middle name, Dark, represents “the unknown.” “People fear it but truly it’s the absence of photons,” Grimes said in the interview. “Dark matter is the beautiful mystery of our universe.”

She also told VF that Sideræl (pronounced “sigh-deer-ee-el”) is an elven spelling of the word sidereal. “[It’s] the true time of the universe, star time, deep space time, not our relative earth time,” she said. Sideræl is also a reference to her favorite Lord of the Rings character, Galadriel. Finally, baby Y’s last name, Musk, is of course the surname of his father.

Grimes told Vanity Fair she initially wanted to name her daughter Odysseus Musk. “A girl named Odysseus is my dream,” she said; however, she and Musk ultimately settled on Exa Dark Sideræl.

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How Vanity Fair come to find out about baby Y is surprising. Reporter Devin Gordon wrote that while interviewing Grimes in her Austin, Texas, home he repeatedly heard a baby cry. This resulted in him asked the singer if she had a second child. Grimes, who Gordon described in that moment as having clenched her body and turned away, initially hesitated to answer the question.

“Whatever is going on with family stuff, I just feel like kids need to stay out of it” she said. Grimes eventually relented, and Gordon said she and Musk used a surrogate for baby Y.

Of course, this resulted in Grimes also giving VF an update on her relationship status with Musk. “There's no real word for it,” she said. “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.”

In September, Musk first told Page Six something similar. He said the two were “semi-separated” but still loved each other and co-parented X together. And, now, they’re co-parenting Y too.

Congrats on the new baby, you two!