The Jonas Brothers hooked up with Jimmy Kimmel last night to talk about their lil bro Frankie (”The Bonus Jonas”) being the most popular, their brand-new book, “Burning Up: On Tour with the Jonas Brothers,” and even took questions from fans outside the ABC studios.

We learned a lot of new things about Nick, Joe and Kevin too! Did you know that Joe, 19, is a certified babysitter. “In New Jersey. There was this girl I liked and yeah…” he tells Jimmy.

Kevin, 21, quickly added, “This was around the time Frankie was born and she said, ‘Hey, this is a good idea.’” Watch the JoBros‘ appearance on Kimmel below!