The pair announced their split in July after nearly three years of marriage, but have stayed fast friends since then.
“Though we are parting ways in marriage, we will remain true friends for the rest of our lives,” the country stars promised in a joint statement.
Now, the bond between the two is as evident as ever as they celebrated Kelly’s 32nd birthday.
To mark the special occasion, Musgraves, 31, shared a black-and-white photo of Rustin looking out of a window on her Instagram story, as captured by Entertainment Tonight.
“Hope you know how lucky the world is to have you in it, @rustonkelly,” wrote the “Rainbow” singer. “Happy Birthday! I’m in your corner.”
Musgraves previously showed support for her ex as he released a new song called “Pressure.”
Kelly shared the song’s audio on Twitter, and Musgraves left a sweet message.
“This song, y’all,” she wrote, sharing the audio with her own followers.
Kelly shared his appreciation by commenting on Musgraves’ post.
“U convinced me to,” he said, adding a black heart emoji.
“With heavy but hopeful hearts we wanted to put our own thoughts into the air about what’s happening. These kinds of announcements are always met with scrutiny and speculation and we want to stop that before it even starts,” said their original joint statement last month. “We believe that we were put into each other’s lives for a divine reason and have both changed each other infinitely for the better. The love we have for each other goes far beyond the relationship we’ve shared as husband and wife. It’s a soul connection that can never be erased.”
“We’ve made this painful decision together — a healthy decision that comes after a very long period of trying the best we can. It simply just didn’t work. … We hold no blame, anger or contempt for each other and we ask for privacy and positive wishes for us both as we learn how to navigate through this,” said the note.