The Little Red Wagon singer was sitting in the audience while her new beau performed with country singer Chris Stapleton at The Greek in Los Angeles when Chris insisted Miranda joined them on stage to sing the classic song My Girl, the 1960s track released by both The Temptations and Otis Redding.
The crowd went wild as Miranda, 32, took to the stage and joined Chris' wife Morgane at a microphone to sing back-up vocals while Anderson took the lead.
This isn't the first time she has performed with Anderson, 27, onstage. On Valentine’s Day, she surprised guests at his show in Northampton, Massachusetts to duet with him on a cover of Mariah Carey’s Always Be My Baby.
It was first reported that Miranda was dating Anderson in December (15), five months after she divorced from fellow country star and husband of four years Blake Shelton, who is now in a relationship with Gwen Stefani.
Miranda previously told Fox News she would be more open and honest about her emotions in her next album.
“I’ve spent a lot, a lot, a lot of time writing lately,” she reveals. “I’ve had more time than I’ve ever had, so I’ve been able to write every day. I think I’ve been more honest - to myself, even. Not being afraid to lay it all out there.
"As I've gotten older I’ve laid it out there less at times in my career but now I’m just like, ‘Here it is, here’s my story'. You can relate because everybody goes through s**t."
Miranda and Anderson made their red carpet debut as a couple at the Academy of Country Music Awards at the start of April (16).