Nick Jonas: Expect Winter Wedding for Eldest Jonas Brother, Kevin

PHOTO The Jonas brothers may end up brawling over who gets to be best man at the oldest member of the boy bands upcoming wedding.Getty Images/
Nick Jonas, left, said he doesn't know if he or middle brother Joe, will serve as best man to Kevin and fiancee Danielle Deleasa (shown in this file photo, right) in July.

The Jonas Brothers may end up wrestling over who gets to be best man at the oldest member of the boy band's upcoming wedding.

In Washington, D.C., Monday, little brother Nick, 16, said he doesn't know if he or middle brother Joe, 19, will serve as best man to Kevin, 21, who proposed to Danielle Delesea in July.

"We've talked about it a little bit," he told ABC News Radio on Monday. "He's working it all out, but we'll see what happens. I'm happy for them and we love her, and we're happy to have her as part of the family."

Nick divulged details about Kevin's upcoming nuptials during Monday's visit to the National Press Club to raise awareness for juvenile diabetes. Nick was diagnosed with Type 1 diabetes in 2005. Since then, he has strived to help children struggling with the disease.

"When I first found out, I didn't know anybody that had diabetes," he said. "So being able to be there, if it's on a TV screen or right there in person with someone, that means the world and I'm happy to do it."

As for Kevin's wedding, Nick said the eldest Jonas may end up tying the knot this winter.

"They have not set a date yet, but I think that it'll be sometime around the end of the year, beginning of the year -- something like that."

Kevin popped the question to Deleasa, 22, in July at her New Jersey home.

Kevin told People magazine that Deleasa "said yes, yes, yes, like 500 times super fast in a row" after he presented her with a cushion-cut diamond ring from Jacob & Co. The couple have been dating since May 2007, when they met while vacationing with their families in the Bahamas.

Brothers Anticipated a Jonas Wedding

Nick told ABC News Radio that he and Joe thought the two were meant to be from the get-go.

"Kevin and Danielle were on the beach walking, and Joe was like, 'Oh, they're gonna get married,'" he said. "And then, a couple years later, they were engaged and now we're here."

ABC News Radio's Andrea Dresdale and Steven Portnoy contributed to this report.