Five-minute memoir: Helen Mort remembers being a fake bride

Iwas 16 when we sneaked into the bridal shop. I was wearing denim flares twice as big as my legs and a T-shirt with Kurt Cobain's face on it. I kept my hair in a bob so short the lads at school called me 'Harold'. As we approached the glass front door, passing under a sign that said 'Virgin Brides' in red and gold, my friend nodded at it and sniggered, "Ask them if you get a discount".

Upstairs, we put on accents softer than our own: we were the son and daughter of a well-known composer, in Manchester for the day, planning my wedding – could they possibly squeeze me in for a last-minute dress fitting?

The receptionist was manicured, with red corkscrew curls. In the window behind her head, I noticed a spot flaring on my chin. I became aware of how damp my chest was, remembered I hadn't washed this T-shirt in days. I didn't smell like a bride-to-be. Perhaps it was just as well I wasn't.

As I scrawled a fake name on the register (someone from school I didn't like) and followed the receptionist into a larger room, stuffed with cream and off-white satin, I tried to remember whose idea this had been. The four of us were on a day trip out from Chesterfield; me, my boyfriend and two friends. We'd been to Pizza Hut and cheated the all-you-can-eat buffet. We'd seen the underside of every railway bridge in town. The novelty of chasing Piccadilly's oily pigeons had worn off after the second hour. We were looking for something we could get away with.

In the white, jewelled room, a second woman took me by the arm and steered me down an aisle of huge gowns, pointing out features of each. I remember thinking there was something about the bodices that made them look like suits of armour. I wondered how people managed to walk in them. Some were dazzling, the colour of hardening snow. Others were almost pink, as if they were embarrassed by themselves. As she ushered me into the dressing room, the dress assistant asked questions about "the big day". I lied effortlessly: I told her I was a freelance athletics journalist and my partner was a lawyer. I invented a spring ceremony in a Derbyshire country house I'd been to once. I muffled my accent. I kept saying "of course".

She went to fetch the first dress, a simple, tapered kind of thing, and I stripped in front of the mirror and stood in my uncoordinated underwear, looking critically at myself: the strange shelf of my shoulders, the bra I hardly needed, my kneecaps swollen from too much running. I usually avoided mirrors at home. I was still cutting the crusts off bread, the rind off meat, still leaving potatoes untouched. Perhaps it was something about the size of all the dresses on the rails, but today, I saw myself the shape I really was. I felt dwarfed by the changing room. My heart was knocking against my ribs, and I was suddenly obsessed by the idea that the assistant had gone to tell the police we were liars.

When she came back at last, she was kind and she didn't seem to mind about my pale, strange body. She helped me into the dress, holding the net skirts gently, fastening each hook and eye. She didn't ask any more questions. She tightened the bodice behind the small of my back and made sure it sat right on my hips. She accidentally stroked my neck. Then she smiled at me, pulled back the dressing room curtain and led me out to where my friends were waiting, furtive in their chairs, trying not to giggle. I saw James putting his fist to his mouth and biting the knuckles. They all stayed very quiet as the assistant helped me up on to a kind of podium.

It was higher than it looked. I glanced down at my friends. I'd thought I'd get the giggles too, but I suddenly felt very serious. I had a lump in my throat and my eyes stung. I wondered if we should own up now. I was gripped with a strange, superstitious feeling. Very quietly, the assistant reached up and placed a small, ornate tiara on my head, perched it on top of my short hair. Everyone was silent for a long time. Then, the assistant said, "Doesn't she look beautiful?". "I feel like a meringue!" I said, so they wouldn't have to answer. In that awkward silence, I realised I wasn't a child any more. But I wasn't an adult either. I stood there, in between things, not exactly happy but briefly content to be the age I was, to stand in my own skin, however ridiculous.

I've been to weddings since, and when I see the bride in her slow procession down the aisle I always think about that afternoon, the sense I had of taking something that wasn't mine.

Helen Mort is five times winner and now judge of the Foyle Young Poet of the Year Award, organised by the Poetry Society and supported by the Foyle Foundation. To enter, visit foyleyoungpoets.org