Grimes and Elon Musk secretly welcomed a second baby together

Singer Grimes sat down for a cover story with Vanity Fair, and the interview uncovered that she had another – secret – baby with Elon Musk. 

Writer Devin Gordon went to Grimes' house for the interview and while talking to the pop star, whose real name is Claire Boucher, a baby cried out. 

After hearing multiple, "unmistakable," cries, Grimes addressed the elephant – or infant – in the room: She was hiding a baby. "She's a little colicky too," Grimes admitted to Gordon. "I don't know. I don't know what I was thinking."

She and Musk welcomed their first child, a boy named X Æ A-12, in March 2020. The name garnered widespread attention, for obvious reasons. While many wondered how to pronounce it, some wondered if it was even legal.

Grimes calls her son X. Their new baby – born via surrogate, according to Vanity Fair – is called Y. She does have a full name: Exa Dark Sideræl Musk.

Exa refers to the supercomputing term exaFLOPS; Dark symbolizes is "the unknown." Sideræl—which she pronounced for Gordon as "sigh-deer-ee-el"— is "the true time of the universe, star time, deep space time, not our relative earth time." 

Grimes and Musks' son's name is pronounced X A.I. Archangel. Musk, 50, is a father to other five other sons – a set of twins, Griffin and Xavier and a set of triplets, Damian, Saxon and Kai, conceived via in vitro fertilization with his first wife Justine Wilson. 

While it was reported in September 2021 that the pair had broken up, Grimes said that is not entirely true.

"There's no real word for it," she said in the Vanity Fair interview. "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."