"I broke the band up, but I got them back together as well," Nick Jonas told host James Corden.
The brothers said they played a drinking game and just got everything out there -- not only as family members, but as bandmates.
When Corden asked about how they got back together, Nick Jonas said a year ago, "We started talking about making a documentary together."
The "Sucker" singers recently announced that in addition to new music, they are partnering with Amazon Studios on a new documentary that will give an intimate look inside the lives of Kevin, Joe and Nick.
"In that process, we did some necessary healing," he said, adding, "When things ended, it wasn't necessarily the best."
The trio realized during that much needed healing that there was a magic they created when they were working together.
Later in the segment, the trio also took a lie detector test, where fun questions were answered like how it's Kevin who gets on Joe's nerves the most.
One of the toughest questions was asked to Nick about his many weddings and festivities he had last year with now wife Priyanka Chopra. He was asked if there was ever a point where he was just "done" with all the weddings.
"Yes," he said, smiling and it was confirmed to be true.
"It was when I looked at the bill," he said, before the entire car erupted in laughter.