Though still unable to marry legally in Australia, the pair, aged 29 and 30, are engaged and wear diamond rings to show it. But on Saturday night, in a match for premiership points between Collingwood and Melbourne football clubs, there will be no love lost. Fiancees will turn on-field foes. At least until the post-match where Clifford and Cula-Reid, once home, will inevitably discuss their other great passion in life: playing footy.

This is the brave new AFL. New thanks to a competition launched one short week ago, to rapturous audience acclaim, by this country's pre-eminent sports code. Brave because never in the storied history of the Victorian Football League-turned AFL has an elite male player declared his homosexuality.

Suddenly, in this infinitely more progressive reality where women are determining what AFL scoreboards say, we have Demon Clifford and Magpie Cula-Reid, a woman who already has serious form in high-profile pioneering.

And just as their love story becomes public today with football as a backdrop, it has the sport at its origin. Cula-Reid and Clifford first laid eyes on each other on a footy field. A humble patch of grass in St Kilda, Melbourne, called the Peanut Farm Reserve and home to many an amateur Aussie Rules game.

It was six years ago. Clifford was a newcomer to the St Kilda Sharks women's football team and Cula-Reid was something of a footy legend, having been the face of a landmark Victorian Civil and Administrative Tribunal case that saw females win the right to play against males beyond age 12.

To command Clifford's attention, and also to teach her a lesson, Cula-Reid literally threw herself at the first-timer to Sharks training.

"I'd never played a proper game of women's football," Clifford told Fairfax Media this week.

"I'd been travelling for three-and-a-half years around Australia, my cousin was training with the Sharks down at St Kilda and so I went along.

"In that first session a ball was kicked deep into the pocket and all I've seen is this girl come across, punch the ball out of my hands and say: 'You have to do better than that to get into this team'.

"I was like: 'Who is this person and who does she think she is, it's my first training!'. But that was Penny; that's my first memory of Penny."

Cula-Reid, a lifelong Collingwood supporter and Sharks player since age 16, remembers the same moment vividly.

"It was probably a classic sandpit situation where you throw sand at the person you like," she reflected with a smile.

Both women had close families that supported their choices in life, relationship-related and beyond.

"I have gay uncles and aunties and cousins," said Clifford, a full-time landscape gardener and, until recently, one-eyed Geelong fan.

"I was brought up to love the person not the gender, but when I met Penny I wasn't 100 per cent sure what direction I was going."

What about Clifford captivated Cula-Reid?

"The way Mia played her footy," she said.

"It was very fierce. And that's how she attacked her life as well.

"Mia's also a very genuine, caring person. She holds her family and her friends really close to her heart."

And traits of Cula-Reid that stood out to Clifford?

"I didn't even know Penny's history but thought it was just amazing to see a girl with so much skill who, at the same time, was so driven," she said.

"I was the free spirit. Penny has always had goals and ambitions. I think that's rare to find in people these days: people with genuine goals who know what they want."

There was no memorable out-on-a-limb romance moment. The pair didn't ever really arrange a first date. Making their relationship "official", about six months in, meant introductions to nearest and dearest rather than a "coming out".

There was no need for explanation at their footy club.

"I'm sure there are others – both genders – in similar situations in sports codes throughout the world," said Cula-Reid.

Why, then, does the duo think the same story hasn't emanated from a male AFL setting?

"I ask the same question but I don't have an answer," Clifford said.

"I guess if there are men who are gay in the AFL it will just take one or two people to come out and things might change. But until that day happens I don't think they know how to handle that."

Cula-Reid senses the time is nigh.

"I like to think people are generally more accepting of everything: of race, religion, sexuality," she said.

"It's all about love, more, now."

Cula-Reid proposed to Clifford in the St Kilda Sharks' clubrooms after her 150th match for the side in 2015. Now signed to AFL clubs, Cula-Reid and Clifford know they could have kept their relationship out of the public domain.

"I think some people want to focus on the football and we want to do that too," Cula-Reid said.

"But at the same time I'm not going to shy away from the fact that Mia's my partner. I feel like I'd be doing her an injustice not to mention her, or if I just referred to 'my partner'.

"I've been asked before: 'Do you want to mention that you have a partner?'. Well, actually of course I do."

The couple holds no fears about backlash from this story.

"We're proud, and proud of each other," Cula-Reid said.

"We're AFL players, we're playing for different AFL teams and we happen to be in a relationship. Once we step onto that field our alliances are with our AFLW clubs. No love lost.

"We're not here to wave the flag for gay rights, we're here saying 'this is us'. And if that helps someone in the future, that's great."