Elon Musk and singer Grimes have welcomed their second child together.

The Tesla CEO, 50, and the musician, 34, welcomed a baby girl one year and some months after they welcomed their son X Æ A-Xii.

Grimes revealed during her Vanity Fair interview that her family had grown after her daughter began wailing from upstairs during the interview.

She didn’t share their daughter’s name in the interview but she revealed that they call the newborn “Y”. The pair also call their son “X”.

Grimes explained that “Y” was born in December 2021 via surrogate.

This is the first daughter for Elon who already has 6 sons.

It comes just months after reports that the pair had separated.

Businessman Elon confirmed that he and Grimes were semi-separated but remain on good terms back in September last year.

However, the pair seem to be back on following their baby news.

Grimes told Vanity Fair: “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.”

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

The couple also want more kids, telling Vanity Fair that they’ve “always wanted at least three or four.”

Elon was previously married to author Justine Wilson, with whom he had six sons. Their first son, Nevada, who was born in 2002, died of sudden infant death syndrome at the age of 10 weeks, leaving them with five sons: twins Griffin and Xavier, 18, and triplets Damian, Saxon and Kai, 16.

He was also married twice to actress Talulah Riley, who wed in 2010 but divorced in 2012.

They reconciled and remarried in 2013 but divorced again in 2016.

Elon also dated Amber Heard from 2017 to 2018.