As lucky fans told the camera about their love for the boy band, the trio and Ellen scared the unknowing participants by jumping out, casually walking by them, or even waiting patiently until the fans turned around. And yes, there was a lot of screaming.
One girl from New Jersey -- who called Nick " the cutest little nugget in the whole world" -- actually fell to the floor when she saw the Jonas Brothers. "You called me a nugget!" Nick said, giving the fan a hug.
"It was hard to tell what was more special me or them," Ellen joked.
But it wasn't only fans who the brothers scared. Ellen took the trio into the talk show's control room where they popped up behind some "Ellen" staffers. One female staffer was so startled she cursed, to which Joe replied, "This is a daytime show you're not allowed to swear!"
During the interview segment, Ellen, who really seemed to enjoy calling Nick a "nugget," joked how she was mad at the group for not coming to see her sooner after they reunited earlier this year.
"I'm very upset because I feel responsible for your career," Ellen quipped and Nick agreed, "You are in fact responsible for our entire career."
The daytime host gave viewers a look back at some of the band's past visits to Ellen. And it seemed the video didn't just make fans teary-eyed.
"That was emotional back there," Nick said. "We watched the clip you just showed. It's been a long ride."
Ellen showed an adorable throwback photo of her and the band, posing with plaques of their 2007 album.
"That was our first platinum record that you gave to us," Nick said of the pic, adding, "So many memories on this stage with you, that stage right over there performing -- both together and solo. So to come back now is really special, so thank you."
The brothers, who are currently on a sold-out tour, spoke about their emotional reunion.
"We really didn't know what was going to happen when we got back together to talk about the idea of doing this," Joe recalled. "It really shows that the fans stuck around and waited and supported us through the individual projects and what we were up to. We announced this thing and the music took off right away. It did feel like okay this is meant to be. We're supposed to do this again."
"It's been beyond amazing to experience this every single night again," Kevin added. "I truly never thought we were going to do it again, and to now have my daughters be apart of it and see it, it's just beyond."
As documented in their Amazon documentary, "Chasing Happiness," it was Nick who both initiated the group's break up in 2013 and their emotional comeback.
"I think all families go through their own version of our story," he said, referencing the film. "And if not, then you're the lucky ones. But you've got to find your dynamic as siblings within your adult relationships when you compound the fact that we were working together every single day. In theory, it was a business. It was a full operating machine. And we were just trying to remain close as family amidst that."
The Jonas Brothers also performed their hit "Only Human" from their album "Happiness Begins" and played a fun little game for Breast Cancer Awareness Month called "don't burst my bubbly." See which brother revealed he's the one who has hooked up with the most fans in the video below.