Grimes the “Oblivion” singer says on Twitter that she and Tesla founder and SpaceX CEO Elon Musk have broken up again. And they have just welcomed their second child together.

Grimes, 34, had just revealed in a Vanity Fair interview that the couple had secretly rekindled their romance to welcome their second child in December 2021. 

In 2020, the busy couple welcomed their son X Æ A-XII, referred to as X. And their daughter’s name is Exa Dark Sideræl, but she will be known as Y.

Vanity Fair cover story reveals second child

In her Vanity Fair cover story, due out in April, Grimes said the on-again-off-again pair secretly welcomed their daughter in December when the surrogate gave birth.  And that she and the 50-year-old billionaire had gotten back together at that time.

“Me and E have broken up *again* since the writing of this article, haha, but he’s my best friend and the love of my life, and my life and art are forever dedicated to The Mission now,” Grimes tweeted Thursday.

 It’s possible that Grimes's “mission” is her 2021 effort to cover her body in extraterrestrial-inspired tattoos. A “long slow effort to have a full alien body” that’s “totally covered in white ink,” as she explained on her Instagram Stories.

“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 explained to the publication.

“This is the best it’s ever been,” she said of their happiness. “We just need to be free.”

 Musk is also a father to five from his first marriage to author Justine Wilson. He has twins 18-year-old Griffin and Xavier. And 16-year-old triplets Damian, Saxon, and Kai.

The uncoupled pair still have plans to expand their family. The singer and performance artist said they’ve “always wanted at least three or four” children together. It’s impossible to guess what baby number three would be named. But he or she will probably be known as Z.