“I couldn’t believe it. I thought it was a joke until I met Eminem myself,” said Jelly after their performance of “Sing for the Moment”

Ayisha Collins/FilmMagic, Kurt Krieger/Corbis via Getty Jelly Roll; Eminem© Provided by People

It’s a sweet treat when Jelly Roll and Eminem come together.

After joining the rapper on stage to perform “Sing for the Moment” at the Live From Detroit: The Concert at Michigan Central event on Thursday, June 6, the country star opened up about the “coolest moment ever” in a new interview with Entertainment Tonight.

“When I think about coolest moments of my career, right now at the top, there has to be this thing that I got to go sing with Eminem in Detroit,” reflected Jelly, 39, to the outlet. “I got to sing ‘Sing for the Moment’ with him, which is a record where he sampled Steven Tyler. I mean, just what an incredible night and I got to go do it in Detroit. It was unreal.”

Aaron J. Thornton/Getty Eminem© Provided by People

Eminem’s team reached out to the “Need a Favor” singer, who recalled, “I couldn’t believe it. I thought it was a joke until I met Eminem himself.”

Despite considering the “Lose Yourself” rapper’s manager a “friend,” Jelly was still pinching himself at the unbelievable opportunity: “His name is Paul, and I was like, ‘Paul, don’t play.’ He was like, ‘I swear,'” recalled the musician. “And as soon as I met Eminem, it was like the coolest moment ever, man.”

The performance was a success — and an extremely exciting moment for Jelly, who told ET he felt “giddy, like a child” on stage.

Jason Davis/Getty Jelly Roll© Provided by People

“You could see it all over my performance. Just the kid in me,” he added. “I thought the camera was off of me. So as soon as I get through singing, I’m like, ‘Whoa.’ I just let this steamroller out. It’s really cool.”

At the Detroit event, Eminem also performed “Houdini,” “Welcome 2 Detroit” with rapper Trick Trick and “Not Afraid.”