Blake Shelton gushes over Gwen Stefani's concert during tour opener

Blake Shelton gushed over Gwen Stefani's concert as he watched with pride from the wings during her tour opener on Tuesday (12Jul16).

The country music star turned out to support his girlfriend as she kicked off her This Is What the Truth Feels Like tour near Boston, Massachusetts and couldn’t help but gush over the show as he watched rehearsals earlier in the day.

"Hey Boston.. I'm so happy for y'all!! I'm here watching @gwenstefani rehearsal right now. Prepare yourselves for greatness!!!," he tweeted.

He later returned to Twitter to post a picture taken from the wings of the stage showing Gwen singing to the crowd and continued to rave about her show. In the caption, he wrote, "Wow... I am a terrible photographer but this is an epic thing to see!!!"

He became even more enthusiastic online after the gig, writing, "Holys**tballs of America!!!!! That was unreal!!!! What was yalls (sic) favorite song?! I loved 'Don't Speak'!!!"

Blake appeared in several of Gwen's Snapchat posts as they hung out backstage before the show, and she later took to Instagram to share a picture of them laughing and snuggling up in what appears to be an airplane.

In the separate post, she wrote, "1st show was amazing - thank you Boston!!!"

Ahead of the tour, reports suggested she was struggling to shift tickets and had slashed prices to just $10 to fill the venues. A video posted on Perezhilton.com on Tuesday (12Jul16) appeared to show rows and rows of empty seats at the back of the Xfinity Center amphitheater, but a picture posted online by a fan showed a crowded front section with only a small empty area towards the rear.

This Is What the Truth Feels Like Tour concludes in 16 October (16) with a two-night stint at The Forum in Inglewood, California.