Is that Dierks Bentley or his '90s alter ego Douglas Douglason? Wait, is that Thomas Rhett?

The mysterious supergroup Hot Country Knights was on hand to open Bentley's Nashville show at Bridgestone Arena on Friday (Feb. 22), and they brought a familiar friend to the stage to perform Rhett Akins' "That Ain’t My Truck," with the "Die a Happy Man" hitmaker sporting a full-on mullet.

Hot Country Knights, Bentley's side gig, is Spinal Tap-meets-Curb Your Enthusiasm, according to them. They go all out with wigs, shades and mullets to bring their crowd cover hits from the '90s and beyond. The band made their debut performances during Country Radio Seminar in 2015.

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Past Hot Country Knights stage guests have included: Miranda Lambert, Randy Houser, Charles Kelley and Kip Moore. Lambert was there for Bentley's show on Feb. 22, too, joining the headliner and other surprise guest Keith Urban for a medley of country classics.

Hot Country Knights — along with real artists Tenille Townes and Jon Pardi — will be supporting Bentley on the rest of his 2019 Burning Man Tour dates.

See Pictures of Maybe Thomas Rhett Singing With Hot Country Knights: