In 2003, Rob Mills and Courtney Act competed on Australian Idol. One night, they had an "orgy".

Millsy, an uncertified icon of Australian pop culture, has some news to share.

It's not particularly timely – in fact, it's about something that happened over 19 years ago. But that hasn't stopped absolutely everyone dropping whatever they were doing to ask the question: What exactly happened in 2003?

Watch: Rob Mills sings You Don't Treat Me No Good on Australian Idol. Post continues after video.

You see, Rob Mills has released a memoir called Putting On A Show, and with it, he's sharing some details of his party days and the antics that occurred around his season of Australian Idol. 

According to Millsy, both himself and fellow contestant Courtney Act, had knock-off drinks after Idol finished taping for the night and things got cosy. Well, we're not sure that's the right word, so we'll use Millsy's own: "Orgy."

“Courtney, me and a woman; I’ll call her Sam. We had a bit of an orgy,” he recalled.

“Courtney and Sam had sex, Sam and I had sex, Courtney and I had sex. There was a lot going on.”

"We had an awesome, drink-fuelled threesome with a woman," he wrote in an excerpt of the book.

Rob Mills and Courtney Act during Australian Idol. Image: Getty.

Mills is currently engaged to Georgie Tunny who is a frequent host on The Project –  but beyond this relationship (and his brief encounter with Paris Hilton), there's not much we know about his romantic life. 

However, in his book it seems this topic is explored quite heavily – particularly during his launch into the spotlight in the early noughties.

“There were subsequent times when, under the influence of alcohol or drugs, I had flings with gay friends and sometimes strangers,” Mills shares in an extract.

His nights out and drug use are things he's spoken about before, sharing with Now To Love that before Australian Idol he was never much of a partier. 

"In my own head, I was a really hard worker. I worked five days a week and then four nights a week in the band, so I never really went out partying. It was only on Idol that I went out partying. It was the first time I'd been on a plane. It was the first time I'd been let off the leash."

It was after Idol that Mills first dabbled with drugs too – sharing that his inability to say 'no' saw him sampling more than he ever thought he would.

"I am saying on the record as a [now] 33-year-old guy, I am completely against recreational drugs, but cocaine is a hell of a drug," Mills shared on Em Rusciano's podcast, Deeply Shallow.

"I was 21, and I had never been out of Melbourne. I think my longest trip was a caravan trip... I did everything [drugs]... I am a 'yes' person."

Rob Mills. Image: Getty.

"To watch Rob Mills write this book has been a seesaw of emotions. Highs, lows and periods of stagnation. But he pushed through it all and created something spectacular," Tunny wrote on Instagram recently. 

"Men need to do better – for humanity but also for their own mental health. As an objective journalist with absolutely no personal interest in the matter, I implore you to read Putting On A Show so that all the people who SHOULD read it get the message and pick up a copy, too. And to Robert, I say: you damn well did it!"

Image: Getty + Mamamia.