Brad Paisley loses bet

Brad Paisley lost big in a bet with rapper Ludacris.

The country star apparently bet his fellow Rising Star judge a $2,100 bottle of cognac. What the bet was is unclear. However, Brad posted a video on Instagram with the bottle of Louis XIII de Rémy Martin beside him and advice for his followers.

"Don't make bets with rappers," the 41-year-old singer said. "They're very expensive."

The video Brad posted also features the 36-year-old rapper, joking "Man, you better not have poured Hennessy in this thing," as he holds up the Louis XIII de Rémy Martin box.

Brad and Ludacris sit on a panel of experts alongside Josh Groban and Kesha on the talent show Rising Star, which invites viewers to vote live for contestants via an app.

Prior to posting the video, Brad tweeted Rising Star "can break world records too. I bet we set a record tonight for most TV uses of the word 'app'."

The first episode of Rising Star aired in the US earlier this month, with Kesha offering a Twitter commentary. She joked that the format reminded her of the dating site, where users swipe right if they like someone and left if they're not interested.

The show's mentors vote in the same way as viewers and then help coach all the lucky hopefuls who make it through.

Kesha recently opened up to Ryan Seacrest about how exciting this new concept is.

"It is kind of amazing and genius and revolutionary," she told the TV star during On Air with Ryan Seacrest. "[The voters] use apps. You just download an app, it's free, and then America gets to vote and it's instantly gratifying. There's no waiting for the results."