Cas Willow and Heather Richards will make history on Monday, when it is likely they will become the first same-sex couple to marry in Australia.
The pair has been in a relationship for 17 years.
Now they are in a race against time.
Cas, 53, has breast cancer that has metastasised to her brain, and may not see out the year.
What they hope for is a precious few days, or perhaps weeks, they will no longer have to explain to the world what they mean to each other.
In Heather's words, their relationship will not just be tolerated, it will be accepted.
It had been expected that the nation's first gay weddings would not take place until early January, as all couples intending to wed usually have to give one-month's notice.
But a trickle of people with exceptional circumstances have been given permission to tie the knot sooner by births, deaths and marriages registries around the country.
Since late October Cas' illness has abruptly worsened.
Just a few months ago, the accomplished counsellor and therapist had been living a normal and busy life, running her clinic in Williamstown in Melbourne.
She believed she had beaten the disease, after invasive treatment that included a bilateral mastectomy, having her ovaries removed and dozens of sessions of radiation and chemotherapy.
"I had to really get my head around it," Cas said.
"I really thought I was done. I knew I had to keep my eye on it for the next couple of years but I thought I had time."
At times in recent months, she has lost her ability to speak.
Cas got her terminal diagnosis two months ago, just a few days before the results of the postal vote were announced. The pair got engaged a minute after midnight the day federal Parliament legalised same-sex marriage.
"We asked one another and lit a little candle. It was beautiful," Cas said.
A mother of three, Cas has been married before - at just 16 - when she said she knew she was gay but did not feel she could come out.
Her youngest daughter Phoebe, 34, is engaged but was unwilling to get married until there were equal marriage rights.
It will be the first marriage for Heather, 56, who said she shunned a commitment ceremony previously because she did not believe it was equal to marriage.
Heather said the wedding would make their relationship complete - and mean that she would be able to carry on Cas' legacy when she is gone, as her wife.
"There is a lot of tolerance out there because people have to be politically correct, but there is not a great deal of acceptance," Heather said.
"It's a bit like having an insincere friend.
"We were playing house for a long time."
It was the staff from the spiritual care team at the Peter MacCallum Cancer Centre, where Cas is receiving treatment, who originally suggested they might be able to arrange a fast-tracked wedding.
The hospital will also host the ceremony on Monday afternoon with the help of its suppliers and contactors who have donated catering and other goods and services.
"We are thrilled to support the celebration of Cas and Heather's marriage, and we are committed to providing a compassionate and supportive environment for all patients and staff of Peter Mac," the centre's chief executive Dale Fisher said.
It is believed the marriage could be the first same-sex wedding in Australia.
Births, deaths and marriages registries in New South Wales, Western Australia and Tasmania have also confirmed that they have approved waivers for same-sex weddings, but would not reveal the wedding dates.
Cas and Heather said it would be an honour and a privilege if they become the first gay couple to be married on Australian soil.
"Loving someone is the easiest thing to do," Cas said.
"Looking after the relationship, that's the thing that takes time and consideration."
