There will be split ties in the Stephen household tonight come kick-off between the All Blacks and Ireland in their Rugby World Cup quarter-final.
Martina will be sporting shamrock-green while her husband Garry dons the famous silver fern on his left-breast, she told the Herald.
Born in County Meath, north of Dublin in eastern Ireland, Martina grew up an avid Gaelic Football fan and had limited rugby knowledge.
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However, after meeting Garry in 2007 while the pair worked for two separate safari companies in Botswana, things had to change.
"When I met Garry I had to learn about rugby," she said, but always remained loyal to the men in green: "First and foremost, I will support Ireland.
"If New Zealand are playing anybody else I'll put my little black jersey on but if Ireland are playing I'm supporting them."
Kick-off for the blockbuster quarter-final in Tokyo starts at 11.15pm (NZT), following the match-up between England and Australia in Oita.
It will be just the second time New Zealand and Ireland meet at the World Cup, after a 1995 pool play clash which New Zealand won 43-19.
The match was being tipped as Ireland's most important ever - and Martina said her Garry would be animated for the match too.
"He's a fanatic rugby player so it's quite a serious thing for him. We'll have a bit of banter ... but it's always good banter," she said.
"Garry reckons if New Zealand has to be beaten by anybody, he'd like them to be beaten by Ireland. Obviously, he'd like New Zealand to win.
"I'm expecting Ireland to win of course. I expect it'll be a good game, a close game and it'll be a win for Ireland - if so, I might be looking for a bed."
A couple made up of an All Blacks and South African fan made a pact at the start of the World Cup the losing supporter would either skydive or crossdress.
When asked if Martina and Garry, who now lived in Taupō, had a similar bet, the Irishwoman said she wouldn't dream of it.
"Oh god no and I'm not going to bring it up just in case!"