Elon Musk, Grimes secretly welcomed a 3rd child together

The pair split up in 2021, though Grimes said her relationship with Musk is "very fluid."

Elon Musk and Canadian singer Grimes privately welcomed a third child together, according to a post the tech billionaire made on X, the social media platform formerly known as Twitter.

News that Musk and Grimes had a secret third child surfaced after the New York Times published a review of Musk’s upcoming biography, written by Walter Isaacson, in which the child is mentioned.

Musk confirmed the rumours in response to a post made by entertainment news account Pop Base, which listed the unusual names of the pair’s three children.

Musk wrote that the child is named Tau Techno Mechanicus. But according to Isaacson’s biography, the child’s legal name is Techno Mechanicus Musk and Tau is a nickname.

According to the unreleased biography, which was obtained by the Los Angeles Times, Techno Mechanicus was born via a surrogate on June 2022. His nickname, Tau, is a reference to the Greek letter that is two times the value of pi, an irrational number important in geometry and mathematics.