Gwen Stefani is really supporting her man!
Gwen took to Snapchat (above) from the four-day country musical festival set up by Luke Bryan, but gave no inclination she would be performing…
So when the country crooner brought out his girlfriend for his encore, the crowd went wild for Stefani as she performed No Doubt's Hella Good.
This is one surprise it sounds like everyone loved!
Catch a couple clips (below):