When I was a child, the house across the street from us was owned by two elderly sisters. I think my mother felt sorry for them, as they had no children or family of their own, and as our real grandparents lived many miles and hours away, she adopted them and so we did too. My sisters and I went for tea on Sundays, and showed them the latest, terrible things we had made at school. After tea, while Kate clucked and cooed over our latest efforts, Betty would reach down beside her and bring out a box of pink wafers, her favourite biscuit.

"Here," she'd say, "don't tell your mother. Or Kate". She would wink at us then, and we would nod, enthralled, and swept up in the conspiracy. For the longest time, we believed totally in our shared secret, and never dared breathe a word of the forbidden luxury, even to each other.

Their house, hardly a time capsule and yet never modern, was filled with things they had collected, and on almost every inch of wall space there hung photos. Many of the pictures were old and fading, affected by years of smoke, those in bright spots and behind Betty's chair yellowing the most. The photos showed them laughing and dancing, perched on the bonnet of an ancient sports car, often with friends, all the women with hair in elaborate curls and all the men in smart suits and hats. The living room was the most crowded with pictures, and where spent most of our time. As the youngest child, I never managed to find enough space on the couch and they brought in a low, white nursing stool, especially for me. In the corner of the room near my stool an old record player stood, with stacks of well loved 78s piled high next to it. After tea on Sundays, they would allow us to choose a record to listen to, push back the table, roll back the rug, and Kate would dance with us each in turn, and sing or hum along to the scratchy tunes. Sometimes, as we crossed the road home, I would hear the record player start up again and imagine them twirling there together, as if long forgotten beaus in uniform had yet again asked them to dance.

As we got older, my sisters grew tired of the same repeated stories, of the endless supply of pink wafers, of the fixed sepia smiles surrounding you from all angles, and went less and less. But I saw that the stories spoke of a time they were most alive, and happy, and how could I deny them that? So there we would sit, me on my nursing stool, and them in their customary chairs, and I would read my stories out loud, and listen to theirs. Often, as they talked, they would gesture with their hands, pointing and stabbing the air with their fingers, conveying myriad meanings their words never would. In time I, too, grew up and moved away, but I always wrote, and told them the parts of my life I thought they were ready to hear. I left out the wild parties, the drunken arguments and one night stands, the realization I liked girls as much as boys, and focused on my sports and academics, on the new dress I bought, or the latest movie I'd seen. The omissions created for me a safe space, that the outside world could not affect, one where I would always be a child, on a nursing stool, eating pink wafers. In the holidays, at Christmas and Easter and in the long hot summers, my visits would resume, and before long we would have fallen into our old, easy pattern.

That world changed, or at least my understanding of it did, late in the summer of 2003. I had gone for Sunday tea and, as always, listened to the afternoon news on the radio. The headline piece was a court decision granting marriage rights to gay couples across the province. Listening to the piece there, in my haven of childhood and innocence, made me uncomfortable, and I hoped they would not ask me why. For how do you explain to women you have loved all your life, women from a different time with different attitudes, that you have lied to them for so long? As the piece continued, they began to gesticulate again at each other, pointing first at me, and then at the other.

"Jo," Kate began, uncertain, "We want to ask you a favour. We want you to help us marry, take us down there, perhaps, and be our witness." I looked incredulously between them, not understanding how we had gone from stories and wafers to here. I must have been too slow in response, for Betty poked me and spoke.

"I'm 90 this year, and I think we've waited long enough." I shifted awkwardly on my stool, and wondered how to deal with this.

"You know," I began cautiously, "the bill is for gay couples, it doesn't mean you can marry your sister". They looked at each other, and laughed.

"I might be old," Betty said, and pointed at me, "but you're the one confused". They told me, then, the major story of their lives – of how they met, and fell in love, and the bumps and bruises they survived in the finding of each other. I realized as they spoke that this was always the unspoken background to all the other stories; it ran through them and tied them together. I listened for hours, enraptured, and when they finished, hands clasped between them, I knew that this had always been unspoken context of our visits, and wondered how I had never known before. The love between them, now my eyes were opened, was palpable, and filled every corner of that house from top to bottom. I looked again at the photos, and saw depicted there two lives intertwined across the years, and saw how special, and yet ordinary, a thing that was.

I went with them to city hall, and was proud to sign my name next to theirs. It wasn't in any of the papers, it didn't make the local news. It was ordinary, so very ordinary, and yet so special too. The photo I took afterwards, the two of them on the steps, smiling into each other, was immediately hung on their wall, my wall now, and that is exactly where it will stay.