When Rascal Flatts played the Grand Ole Opry Tuesday night, they weren't expecting country legend Vince Gill to pop by … let alone with big news for the band.
Under the guise of collecting $500 from the trio after he "kicked their butts" on the golf course, Gill walked unannounced from the wings and took center stage.
The bandmates figured he was pulling one of his infamous pranks. "But when he said, 'On behalf of the Grand Ole Opry,' everything kind of slowed down, and we knew something big was happening, bassist Jay DeMarcus tells PEOPLE exclusively.
Indeed it was: Gill surprised the band with a long-awaited invitation to officially join the Opry. "My initial reaction was tears, but I knew we had to play another song!" says guitarist Joe Don Rooney. "I'll probably cry like a baby when I get home tonight."