Technology billionaire Elon Musk, 48, and singer Grimes, 32, welcomed a healthy baby boy this week.
And the entrepreneur got the world talking when he revealed the name of their baby in a tweet, the somewhat unusual choice of X Æ A-12.
When Musk tweeted, "Mom & baby all good," a fan replied saying: "We need the name we literally need it".
Musk then quickly responded, saying: "X Æ A-12 Musk". It was here that he also confirmed he had welcomed a son.
How to pronounce X Æ A-12
Both parents have since taken to social media to clear up the mass confusion over how to pronounce their son's name, although it seems they each have slightly different ideas.
New mum, Grimes explained X as "the unknown variable" and the choice of Æ to honour the "elven spelling of Ai (love &/or Artificial intelligence)".
She added that "A-12 [is the] precursor to SR-17 (our favourite aircraft). No weapons, no defences, just speed. Great in battle, but non-violent" and said that the A is for Archangel, her "favourite song".
Given Grimes's explanation, baby X Æ A-12's name would be pronounced "Zai-ah", like the name Isaiah without the first syllable.
Musk has since added an interpretation of his own, explaining to podcast presenter Joe Rogan, "it is X, the letter X. The A E [Æ] is pronounced 'Ash' ... and then A-12 is my contribution [for] Archangel-12 the precursor to the SR-71, the coolest plane ever."
"My partner is the one who actually mostly came up with the name," he said. "She is great at names."
Given that each parent seems to have a different interpretation of the name, it's no surprise that many people on the internet also have varying ideas of how it might be pronounced.
Redditor NewFolgers, went into more detail, writing: "The name for the ligature Æ is 'ash' ... so in the name, it may be pronounced that way.
"The Lockheed A-12 was part of the Archangel internal design effort ... So maybe they're thinking: X Ash Archangel Musk".
Others have suggested that the X with the Æ [Ash] and A could be pronounced Sasha, making the baby Sasha Musk.
There is also the possibility, looking to Middle English, that the Æ will simply have an 'eh' pronunciation, if you take the example of King Æthelstan, which is pronounced Ethelstan. In that case, baby Musk's name would be more like 'Xea', pronounced 'Zey-ah'.
Musk is already father to five sons, Damian, Griffin, Xavier, Saxon and Kai from his first marriage to Justine Wilson. The couple lost their first child, a boy named Nevada, to sudden infant death syndrome (SIDS) in 2000.
With baby X Æ A-12, there is a clear influence from Grimes, whose real name is Claire Elise Boucher, and who has a song called 4ÆM on her 2019 album, Miss Anthropocene.