Musk told Page Six that although they “still love each other, see each other frequently and are on great terms”, their careers often keep them apart for long periods.
Grimes is yet to comment on the status of her relationship with him.
The couple who began dating in 2018, welcomed their first child, named X Æ A-Xii, in May 2020.
Musk said “It’s mostly that my work at SpaceX and Tesla requires me to be primarily in Texas or travelling overseas and her work is primarily in LA… She’s staying with me now and Baby X is in the adjacent room.”
The pair were last seen together earlier this month while they were leaving the Met Gala. Grimes walked the red carpet alone but her billionaire partner later joined her inside the event.
The SpaceX CEO was previously married to Canadian author Justine Wilson, with whom he has five sons: twins Griffin and Xavier, 17, and triplets Damian, Saxon, and Kai, 15.
Musk was also married to Westworld actress Talulah Riley twice. Their first marriage was in 2010 and they divorced in 2012. They reconciled and remarried a year later, before divorcing again in 2016.