I lay on my bed and looked up at the ceiling as my new husband, Robert*, rolled off me.
Maybe we just need to practise, I told myself.
Robert was very prim and proper so we hadn't had sex before we'd got married.
We'd met when I was 19 and he was 23.
I didn't have much confidence and didn't think anyone would ask me to marry them so when Robert did, I said yes.
There was little chemistry between us but I assumed once we were man and wife our sex life would take off.
But that wasn't the case.
It wasn't completely fruitless.
A year after our marriage we had a son, John, and five years later our daughter, Rachel, followed.
I wasn't happy in our marriage, but I didn't know any different.
Then we bought a plot of land to build our house and a year later met our new neighbours Rita and Terry.
Terry was short, dark and thickset, the complete opposite to my tall, fair husband.
Robert was a lecturer whereas Terry was a tradie.
Terry and Rita seemed a strange match.
While Terry's hands were usually covered in engine oil from tinkering with his car, Rita was always beautifully made up.
Rita and I became friends and we'd talk for hours over the back fence.
One day, another friend lent me a series of self-help books.
One chapter that stuck in my head was about couples who swapped partners – swinging.
I wondered what it would be like with another man.
I longed for someone to sweep me into his arms for a night of unbridled passion.
Next day, I passed the books over the fence to Rita: "These will open your eyes," I said.
Later that week, I was hanging out the washing when Rita appeared.
"Swinging sounds thrilling," she said, a sly smile creeping across her face.
Giggling, we agreed to ask our husbands what they thought.
But Robert said no.
I was disappointed.
Especially when Rita told me that Terry was up for it.
Three weeks later, out of the blue, Robert came home from work with an announcement.
"I've changed my mind," he said. "Let's give it a try."
Excited, Rita and I came up with a plan.
Our families would go on a two-week caravanning holiday together that summer.
The first week, Robert and Rita would have a day away together and the following week, it would be my turn to have some fun with Terry.
Each couple could do whatever they wanted but the rule was they weren't allowed to talk about it with their spouse afterwards.
We started inviting Rita and Terry to our house to play cards in the evenings, so we could get to know one another better.
Doing something so normal, while knowing what lay ahead, made us feel naughty and excited.
"I don't think I can wait until the summer," Rita confessed to me one afternoon.
She and Robert went to a hotel while Terry and I looked after the kids.
Once the little ones were in bed, Terry and I threw ourselves at each other.
Before I knew it, we were in bed.
It was incredible.
Later that night, Robert wanted to know if anything had happened.
"We're not supposed to talk about it," I said.
But he kept asking and eventually I told him.
It turned out he and Rita had pulled over in the car and started kissing but at the last minute, Robert lost his nerve.
Rita was devastated.
The following week, Terry and I went out to give Rita and Robert another chance and this time they ended up sleeping together.
Before long, the caravan holiday rolled around and Robert and Rita went off together to a nearby hotel.
They were supposed to come back before the kids went to bed, but as night fell there was no sign of them.
Terry was furious.
It was the 1970s so there were no mobile phones, all we could do was wait until they finally turned up late that evening.
The following day, we set off for a different campsite.
But Robert took a turn and wound up in hospital with sunstroke.
I went in to see him.
"Do you love me?" he asked.
Although I was fond of him, I wasn't in love.
"It's over then," he said.
And just like that, our marriage was finished.
When we got home, Rita and Robert said we needed to talk.
"We've decided to give our relationship a go," Rita announced.
They said they were going to set up home together and all four children would live with them.
I was stunned.
I'd never expected our holiday to end like this.
I didn't want to tell my parents what was going on, and without a job, I had no money to support myself and the children.
In the end, it was agreed that I would live with Terry temporarily, and my daughter Rachel would stay with us along with Terry's youngest daughter.
As I lay in bed that night in a filthy house, just next door to my lovely home, I sobbed uncontrollably.
It had all happened so quickly and now I was with a man I barely knew.
The next day, a bailiff came knocking at the door and I discovered Terry was in huge debt.
I'd been such a fool.
Over the next few months, I tried to make the best of a bad situation.
I got a job as a secretary and worked on my relationship with Terry.
Although I wasn't in love with him, the sex was incredible.
But we were the talk of the town.
A year after the wife swap, Robert and Rita moved away.
Terry was extremely possessive, and we had furious arguments.
After living with him for seven years, I left him and moved back in with my parents with Rachel, who barely spoke to her father.
It's been 46 years and I still think about the wife swap and all the hurt it caused.
Although I didn't love Robert, we'd created a stable home.
But the swap split Rachel and her brother John up, and ruined her relationship with her dad.
I can't believe I risked the safety of our marriage for a single night of passion.
It's the greatest regret of my life.