'The one thing I wish I knew before my 10-year relationship fell apart.'

When Jessica* met her partner at 21, love was the priority. Money? Not so much.

She was young and in love, falling deeper into what would be a 10-year romance. Finances weren't at the forefront of her mind — until the day everything fell apart.

When their relationship ended, Jessica knew they'd have to sell the house they were building together. What she didn't know was that her ex would be entitled to more than just what he'd contributed — including a share of the sale and her super.

It's a confronting reality, and one Jessica is now determined to talk about, so other women can protect themselves.

"As the relationship went on, I would always check-in with him about his savings," Jessica told Mamamia.

"He was never transparent, wouldn't show me how much he [had] in his bank account … I think he just felt ashamed."

Jessica trusted him anyway.

Watch: How to support someone going through a separation or divorce. Post continues below.

He wasn't cruel or controlling. But she could tell that her well-paying job as a psychologist made him uncomfortable.

"He would never outwardly say it, but I could tell through gestures or body language that you know going out to fancy dinners, or buying us tickets to go on a trip would put him in an awkward position," she said.

"I think because I could feel this I overcompensated and from memory I said, 'While I have this job and income, I can put more away.'"

At the time, it felt fair. Jessica assumed things would balance out in the long run — maybe he'd contribute more later, when he could.

But with hindsight?

"This was quite naïve," she said. "In my mind I probably thought, as life goes on, things will become more equal… But now, if I look at his family dynamic and personality, I don't think it would've.

"I think I would've spent a lot of my time doing things for us because I knew that he couldn't or wouldn't, and I had a lifestyle that I wanted and if he was going to be a part of that life, then I'd need to make financial sacrifices to enjoy it.'

When the relationship ended, Jessica had no idea what came next in terms of their finances. She turned to a financial advisor for help.

At first, her ex agreed to be bought out. Then he changed his mind — he wanted to wait until the property was built and push for a higher valuation.

"The financial advisor told me very early on his exact words: 'Regarding the negotiation between you and Sean*, I would strongly suggest establishing a written (and binding) agreement on how to settle the ownership of the property before it is built'," Jessica recalled.

Jessica didn't worry. She was sure her ex wouldn't screw her over. He wasn't that kind of person.

"My financial advisor said to me things change when money is involved and boy, was he right," she said.

"People started getting in my ex's ear. He started demanding more money.

"I recall standing in the courtyard at work crying on the phone to him, asking him why he was doing this."

When she finally saw a lawyer, she was shocked: despite putting in most of the deposit and taking charge of the build, her ex was legally entitled to more.

So… how is that fair?

It feels completely unfair — you put in more money, took on more risk, maybe even took out the loan in your name. So how does it make sense that your ex walks away with 50 per cent of the sale?

The short answer: Australian family law looks at more than just who paid what.

When a de facto relationship ends, property is divided based on what's 'just and equitable', not automatically 50/50. But in practice, if there's no financial agreement in place, a lot of splits end up close to even — even if one person contributed significantly more upfront.

That was Jessica's reality.

She remembers telling her lawyer, "What's the point of getting into a relationship?" Her lawyer had a simple response: she tells all her clients to get a prenup.

Jessica was furious. She'd worked hard for everything she had — six years at uni, a demanding career, no financial help from family.

"I took on so [many] of the relationship duties," she said. "I found us the rental — I didn't need to leave home and pay rent, I took time off work to go to all the building meetings (he didn't). I didn't go on a 'find myself' holiday to Europe when we broke up because I knew we had a house to build and responsibilities. And now you're telling me he can take my money and my super?

"I felt like I was going through a divorce at 30."

It's something she never even considered when she first fell in love at 21. Now, she wants others to think about it.

"My parents taught me how to protect my money from myself (stop buying a new pair of shoes every week) but no one taught me how to protect my money from others," she said.

"I wish before we moved in someone sat us both down and said, 'Now, do you know what it means legally to be considered de facto?' I think that would've forced us to have a conversation."

These days, dating looks different for Jessica. Romance isn't dead, but it comes with paperwork.

"My next relationship comes with a financial agreement and if they aren't willing to sign one, that just means: one, you don't understand or respect my rights as a working woman or two, you're probably going to f*** me over if this relationship ends."

*Names have been changed for privacy.

Feature Image: Getty.