Elon Musk and Grimes welcomed a baby girl they call Y

Tesla CEO and founder of SpaceX Elon Musk and Canadian musician Grimes have welcomed their second child together!

In a recent interview with Vanity Fair, the singer revealed that she and Musk have welcomed a baby girl via surrogacy. While she didn’t reveal when the child was born, Grimes said her name is Exa Dark Sideræl Musk. The couple, however, calls her “Y.”

Grimes says “Exa” is a reference to exaFLOPS, a term that describes supercomputing performance. Dark, she says, means “the unknown.” Along with the nickname “Y,”  Grimes said she and Musk sometimes call her Sailor Mars, but that she also wanted to name her Odysseus.

Grimes revealed on Twitter that she didn’t mean for Vanity Fair to find out about her daughter, as the infant’s arrival was only revealed when Vanity Fair reporter Devin Gordon heard the baby crying while conducting the interview for a cover story about the singer. Grimes is asking fans to “please respect her privacy as I’d love her to be able to live as private of a life as possible,” she tweeted.

Grimes and Musk have made headlines lately for what seems like an on-again, off-again relationship, but in her Vanity Fair interview, she explained that their partnership just isn’t easily defined.

“There’s no real word for it,” she told VF. “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.”

When Gordon asked whether they’re happy together, she replied in the affirmative.

“This is the best it’s ever been…. We just need to be free,” she said, adding that we should expect more children from the pair — they’ve always wanted “three or four” kids.

The couple’s first child is a boy born in 2020 named X AE A-XII. Nicknamed “X,” he was originally named X Æ A-12, but “Æ” and “12” violated California law for not being part of the modern English alphabet.

Musk also has six sons with Canadian author Justine Wilson. Their first son, Nevada, died at 10 weeks old from Sudden Infant Death Syndrome. The former couple has five sons today, one set of twins and a set of triplets.

Congratulations to the happy parents!