The pair will be watching at home in Birmingham while wearing the Mr and Mrs South Africa and England shirts bought for them as a wedding present.
“Rosie and I will be happy for the other whatever the result – even if bragging rights will be decided for the next four years,” said Ken, 37, a wine merchant originally from Johannesburg.
“As a couple, we’ve always been into rugby and the World Cup final hasn’t really come into our relationship, even if Rosie has awful memories of the 36-0 game she witnessed in France in 2007,” he said.
“We have seen many games together including some in New Zealand in 2011, England in 2015 and many Six Nations games.”
So who will win the trophy this time around?
“It will be a great match and I just hope England win,” said Rosie, 31, who works as a merchandiser.
Former World Cup winner Jonny Wilkinson puts Owen Farrell through his paces as England gear up to take on South Africa on Saturday
Ken was also quietly confident: “As I live here now, I have seen England play many times and know they will be amped for the opportunity to win their second trophy. They are the best England team I’ve ever seen, so chances are good.
“But… I’ll always be a South Africa supporter and back the Boks in any match, especially a final.
“This year, we’ve seen some incredible rugby and the final will just turn up all the pressure so the team that manages to play their game on the day will lift the trophy.”
Both agreed that Rosie will be the loudest of the two during the big match but, as Ken confided, “it’s her dad and brother that will be unbearable for the next four years”.