Grimes Shares Video of Elon Musk Cradling Newborn Son X AE A-12

Grimes and Elon Musk are settling into life at home with newborn son X Æ A-12 after the Tesla CEO and singer welcomed their first child one week ago. One day after her first Mother's Day, the 32-year-old new mom took to her Instagram Story to share a video of her boyfriend bonding with their son.

In the adorable clip, Musk pats his son on the back as the week-old X Æ A-12 rests on his father's chest, clad only in a diaper. Grimes, whose real name is Claire Boucher, loved the video so much that she added a heart emoji to the footage, zooming in on the newborn's tiny body.

X Æ A-12 is Grimes' first child, but Musk's sixth, as he has five sons from a previous relationship, including son Nevada, who tragically died of SIDS at 10 weeks old in 2002. The couple's choice of such a unique name immediately garnered headlines, and both parents have come forward to explain the pronunciation differently in the subsequent days.

Musk revealed his pronunciation on Thursday's episode of The Joe Rogan Experience podcast, explaining it was Grimes who "mostly came up with the name," adding, "Yeah, she's great at names." As far as Musk is concerned, X Æ A-12 is pronounced with X "like the letter," while "the 'Æ' is pronounced like 'ash.'" Grimes, however, described the pronunciation differently on Instagram the same day, telling a follower, "It's just X, like the letter X. Then A.I. Like how you said the letter A then I."

The couple has revealed that the A-12 portion of their son's name is a nod to the Lockheed A-12 reconnaissance aircraft built by the U.S. Central Intelligence Agency, which Musk called "the coolest plane ever" to Rogan. Grimes added of the other parts of the name that X was for the "unknown variable" and the Æ is her "elven spelling of Ai (love &/or Artificial intelligence)." Some have noted, however, that California statue only allows the 26 characters of the English language to be used on birth certificates, excluding numbers, Roman numerals, accents, umlauts or other symbols or emojis from being officially recognized. The couple has yet to address this barrier.