Blake Shelton and Trace Adkins have been friends for a while — a long while, based on a throwback photo that Shelton shared that is country gold.

Shelton presented the gift to Instagram on Aug. 25. The old photo is of him and Adkins together way back when — both are wearing cowboy hats and western-style jackets, with the "Every Time I Hear That Song" singer rocking his signature mullet. As if the outfits aren't great enough, Adkins makes the photo that much better by making a kissy face at Shelton, who beams at the camera.

"What a di--head," Shelton writes lovingly alongside the hilarious photo. "You never were a very good influence on me!! I still love ya though brother."

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Adkins and Shelton teamed up professionally in 2009 for "Hillbilly Bone," which scored the two country stars a No. 1 hit on Billboard's Hot Country Songs chart and a win for Vocal Event of the Year at the 2010 ACM Awards. While The Voice judge has invited many of his country music friends like Luke BryanShania Twain and Tim McGraw and Faith Hill to mentor his contestants on the show, Adkins reveals why the invitation has not been extended to him.

"He said I was too mean,” Adkins tells Fox News. "He said some of these people are fragile and they don’t need to be subjected to me."

Shelton recently released a six-song live EP from his surprise set during 2017 CMA Fest that includes some of his signature hits like “Home,” “Boys ‘Round Here” and “A Guy With a Girl.” He returns to The Voice for Season 13 in September.

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