In 2019, bestselling Australian author Sally Hepworth was on the top of the world promoting her latest acclaimed novel, The Mother-in-Law. 

At the same time, she was submitting her next book to various editors. But one editor didn't even finish reading her draft before telling her there were problems with it. 

Sally Hepworth sat down with Mia Freedman on the Lady Startup podcast to explain why her soon-to-be-released book topic was so controversial - and why she stands by the idea. 

It all revolves around marriage, monogamy and swinging.

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When Sally was writing The Mother-in-Law - a book about family relationships - she knew her next book would explore marriage, specifically, sex in marriage.

Then, she came up with the idea that her latest book would follow three couples, all in a different crossroads of their marriages. And it would all take place at a swingers party.

"When I came up with the idea, I had very little idea about what a swingers party was. I had an idea that maybe we all have, that it was a '70s style, keys in the bowl type party," Sally told Mia Freedman.

"So of course, I started to research. I read a lot about swinging, or consensual monogamy as it's called or 'the lifestyle' is another name [for swinging]. And when I started to dip my toe in, I realised I need to experience this."

Listen to the whole interview between Mia Freedman and Sally Hepworth on the Lady Startup podcast here. Post continues below.

No, Sally didn't actually experience swinging, but she needed to understand what happened at these exclusive parties and why couples attend them.

"There are lots of ways people do it. There is a thriving online community, there are apps and there are these parties; and there was one coming up in Sydney," she explained.

"I spoke to my husband and he was a bit discombobulated by the idea, but I talked him through it. The one [party] we were looking at had a lot of rules though. You had to be under 40, which we just scraped in at the time, you had to look a certain way, submit a photo and it was a fair bit of money — about $1000.

"So off we went. It was very hidden in the sense that we only found out where to go on the day, it started at 9.30 at night so I had to have a nap during the day and it was a masquerade  — we got our masks at Spotlight." 

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Out on the town ... book research can lead you to some very strange places 🤭😬🤔

A post shared by  Sally Hepworth 📚💄👗 (@sallyhepworth) on Jun 23, 2018 at 3:48am PDT

As for what she wore... 

"Apart from my Spotlight mask, I wore a little black dress, tights and boots. Everyone dressed in a similar kind of style. But what was interesting was that we were the oldest people there by quite a long way. Most of the people were in their 20s — super gorgeous and attractive," Sally told Mia. 

After attending her first swingers party, Sally quickly learnt that swinging was not at all what she had envisioned.

"Very quickly, probably within 20 minutes, an orgy started," she recalled.

"Christian [Sally's husband] said, 'Do you want to go and have a look?' And I said, 'No, but I think we have to. That's why we're here.' 

"We walked in and there was the most amazing orgy I have ever seen," Sally continued.

"They were all on the bed — there were probably 12 people. Women and men and men and women and women and men. It reminded me of a dance of snakes, it was like it had been rehearsed. It was magnificent and yet terrifying."

Sally's discomfort soon disappeared once she began chatting to the people at the party. 

"Later in the night, I was sitting on the couch and talking to various people. I really wanted to understand what people were doing there and why; and people were open [with me]. There were a lot of women who were bisexual, who didn't want to lose their primary partner or their husband but wanted to explore their sexuality with their husband," Sally explained.

"I was in the middle of talking to this woman about this and I look to my right and there was a threesome happening on the couch. I then just carried on with the conversation because you know, I'd just became desensitised to it."

You can read more from Sally on her website, follow her on Instagram and buy her book The Mother-in-Law here.

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Feature image: Instagram/@sallyhepworth