For years, Bonnie Mitchell's relationship had seemed blissfully "normal".
Sure, during their eight years together James* would always spend weeks away from her as he had to travel for work, a situation that Bonnie accepted even if she missed him terribly.
But in 2011 things came to a screeching halt when she and James were woken in the middle of the night by a knock on the door of the home they shared together.
"I remember saying to him, 'who is that?'," the Perth woman told news.com.au. "And he looked at me and I said, 'I'm not opening the door unless it's the police or my mother.'
"Then the person went away and he got up and said, 'I think I know who it is, I'm going to go and sort this out', and he left."
But that wasn't the end of things, with Bonnie later discovering the woman at the door had been James' other partner – a woman he had dated for their entire eight-year relationship, as well as the seven years prior.
Not only had James being seeing this woman but he also had built a life with her that was unsettlingly similar to the one he had with Bonnie.
Bonnie opened up about the relationship on SBS' Insight, revealing how the affair had left her emotionally scarred and diagnosed with PTSD.
'IT WAS LOVELY'
Bonnie, now 42, began dating James when she was 25 after the pair met through mutual friends and got on "like a house on fire".
He showered her with love and attention, he was nothing like her past boyfriends, who had all been "broke" or uni students like Bonnie.
"It was lovely, nobody had ever done that to me before," she told news.com.au.
"He'd left flowers on my doorstep and take me out … he'd make effort to come and pick me up from uni and take me out to dinner, lots of phone calls and chats online."
However nine months in, James revealed he had slept with his ex six months prior.
It was the ex James had been with when they first met, and Bonnie had believed the two had split before she and him started dating.
Bonnie was devastated, but also felt she was "invested" and "wanted this relationship to work", so they stayed together through what she thought was a one-time "slip".
"That caused quite a bit of conflict in the relationship at the time, and to this day I still don't know why he told me that. I don't know why he wanted me to know that," she said.
"I don't know if he was trying to test me, I don't know if he was trying to see if I was loyal to him … I don't know why he told me that at that time when of course he was still seeing her."
'I WAS HAPPY'
Bonnie and James moved past the infidelity and over the next few years did all the normal things couple do.
"Certainly in those early years I was happy more than I was not happy," she said.
While James would usually spend two weeks on, two weeks off with Bonnie for what he said was work – and would sometimes have to leave suddenly for jobs – she was never suspicious.
"He was really good at lining up when the flights came, he knew to check flight's schedules and stuff like that," Bonnie said.
"He was always around when he said he was around, so if a flight was delayed he would not come back early. I was always able to check."
Bonnie moved into his house and even began looking at IVF, a process James "was invested" in.
"He would occasionally take me into a jewellery store and get me to try rings on, but he never actually proposed, he never actually asked me to marry him," Bonnie said.
"It was always the potential of (marriage) … I think it was just another thing to keep me on the hook."
'NONE OF IT ADDED UP'
One night in October 2011, Bonnie and James were in bed together when they heard a knock at the door.
Bonnie refused to open the door but James got up and left, saying he thought he knew who it was but giving no further detail.
James returned the next morning, telling Bonnie the woman had been "his ex" and she had been asking him to buy her out of the property they shared – a house Bonnie had never known existed.
"He was still calling her 'the ex' and I just knew there was more to it because whose ex comes and knocks on the door, eight years after being with someone?" Bonnie said. "None of it added up."
James refused to elaborate, saying he was tired and wanted to sleep. It was only in the evening that he admitted the truth – he had been living with his "ex" at a house just 20 minutes away.
"We didn't talk until later that night but it all came out," Bonnie said.
"And I think it was only because I guessed and I guessed right – that he'd been seeing her the whole time."
While her first reaction was anger at the deception she quickly became "really, really calm" as she realised she had been "eight years with someone who had lied for every part that we'd been together".
Bonnie left the house they had lived in together that night and never came back, with her family and a close friend clearing out her belongings for her.
'I WAS A MESS'
In the months that followed, Bonnie said that she "was a mess" and struggled to cope with the betrayal.
"I ended up with PTSD because I'd lost eight years of my life where I'd been lied to every single day," she said.
Bonnie and James' other partner ended up getting a "three-way divorce" in September 2012 – the first of its kind in Western Australia.
While neither women had been married to James, because he lived with both of them they were his de facto partners.
Bonnie has since met James' other partner, with the women discovering their lives had been eerily similar.
"She was lovely, she was kind to me and I didn't really expect that, I didn't know what to expect," Bonnie said.
"When we talked and realised how similar things were, down to travel and flights and the stuff he'd done with both of us, it still makes me sick to my stomach."
Also unsettling was the physical similarities between the two of them.
"Meeting her for the first time she looked more like my sister then my sister does, we could be related to look at us," Bonnie said.
"I think that's why now I look so different, I actively changed my appearance so me and her don't look alike."
Bonnie has been left with "significant trust issues" and hasn't had a serious relationship since James.
"I am that girl who needs to see your phone and that girl that needs to see your emails," she said. "I don't think I will ever be able to trust completely again."
* Name has been changed.