"We're a little bit amazed, a little bit excited, not quite sure it's real."
However, a last minute twist in the competition has placed all of the wedding preparations into the hands of Mr Rawstorn and Mr Andrew - and vice versa.
"They get to make all the decisions. It's pretty crazy," Ms Briscoe said. "I'm thinking about sending them a cake basket."
The two couples had already become familiar over the course of the competition, but they would know one another "a hell of a lot better" now, she said.
While the pair will have almost no say on the details of their special day, they don't think the boys are about to stitch them up.
"I think the other boys will do really well. We've been having a chat about how they see their day going and ... it's all very tasteful," she said.
The two couples will be wed simultaneously, and then share a split room for separate receptions.
Ms Briscoe and Ms Ivess met on a Kiwi Experience bus tour on the West Coast more than three years ago and have been saving for their wedding since the same-sex marriage bill was passed in April this year.
Ms Briscoe, originally from the UK, said the news hadn't quite sunk in yet, but it would probably hit them on their return home to Paihia.