Gwen Stefani Celebrates Blake Shelton's Birthday By Performing Their Duet

The country singer turned 40 on Saturday.

ByJOI-MARIE MCKENZIE
June 19, 2016, 11:56 AM
PHOTO: Singers Blake Shelton, left, and Gwen Stefani attend the 2016 Billboard Music Awards at T-Mobile Arena, May 22, 2016 in Las Vegas.
Singers Blake Shelton, left, and Gwen Stefani attend the 2016 Billboard Music Awards at T-Mobile Arena, May 22, 2016 in Las Vegas.
Frazer Harrison/Getty Images

— -- Blake Shelton celebrated a milestone birthday Saturday as he turned the big 4-0. His pop star girlfriend, Gwen Stefani, was right by his side.

The two celebrated by performing their duet "Go Ahead and Break My Heart" at Country Jam in Grand Junction, Colorado. Stefani, 46, surprised concertgoers by hopping onstage at the end of Shelton's two-hour performance.

Stefani retweeted a fan's video of her surprise appearance Saturday night.

The former "No Doubt" frontwoman also posted several childhood photos of Shelton in honor of his birthday.

She captioned one photo on Twitter: "Happy birthday to my favorite person I ever met @blakeshelton gx #superbabe."

Stefani also took to Instagram to share another throwback photo of Shelton, with the caption: "Happy birthday to @blakeshelton literally my favorite person gx."

In addition to the older photos, Stefani posted a current photo of herself blowing a kiss to the birthday boy.

Stefani and Shelton began dating publicly last November.

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