However, how that will work remains a mystery -- even to them.
"We don't know!" Nilsson told Jimmy Kimmel, when he asked about the rules on his late night show. "You're pitching ideas right now!"
When he suggested that maybe the producers will make up the rules as they go along, Bristowe laughed: "I believe you!"
Nilsson and Bristowe, who both competed for Chris Soules' affections on the ABC reality show, told Kimmel that they were both confused when they got the call about the new "Bachelorette." Neither was especially excited to be sharing the honor.
"I mean, it's probably not ideal but I think we're handling it well," offered Bristowe.
"If it had to be anybody, I'm glad it's Kaitlyn," she said. "It's like we won the lottery together. So you share it, but it's still good!"
The new season of "The Bachelorette" will premiere May 18 on ABC.