Everyone has heard of sexually transmitted diseases, but in this liberated world in which we live, financial advisers say sexually transmitted debt is becoming an increasing problem.

Key points: Sexually transmitted debt is debt you catch from your partner

Sexually transmitted debt is debt you catch from your partner Can come from rental agreements, guaranteeing loans, signing contracts

Can come from rental agreements, guaranteeing loans, signing contracts Expert says talking about money in a relationship is key

"Sexually transmitted debt is debt you catch from your partner," Melissa Browne, chief executive of A&TA Accountants, said.

"It's not necessarily malicious, but the end result is, whether or not the relationship has ended, you can end up with debt simply from being in that relationship."

Ms Browne said sexually transmitted debt can be just as long lasting and damaging as any sexually transmitted disease.

For example, you can contract sexually transmitted debt from something as simple as wanting to help your boyfriend buy that phone he has always wanted.

His terrible credit rating may prevent him from buying the phone himself, so you get a phone plan for him and put it in your name.

Two months later the relationship has ended and he has left, after racking up a big bill with his new phone.

His present to you is a phone contract and his phone debts, which you have to pay. Merry Christmas.

Sexually transmitted debt can also come from a car loan you may have guaranteed, the rental contract for your home, or any other purchase where credit is involved.

But there are other ways.

Ms Browne tells the story of a couple who were in business together.

The husband did the client facing work while his wife did the accounts.

He assumed all the bills were being paid. He did not know that his wife had a gambling problem and was putting all their money through poker machines.

The ignorance of his wife's addiction did not save her husband.

She was made bankrupt and he was close to following her as he struggled to find the money to pay the business' debts.

Ask the question: What if everything was to go wrong?

Ms Browne said just as we should take precautions to avoid sexually transmitted diseases, we should be just as vigilant when it comes to sexually transmitted debt.

"When you enter a new relationship, or when your circumstances change, you need to ask the question: 'What if everything was to go wrong?'" she said.

"In the phone example, if that person had asked, 'what if we split up?' she may have bought a second-hand phone with a pre-paid plan, which would have protected her from sexually transmitted debt.

Ms Browne said the "what if" question is even more important for bigger issues, such as being asked to be director of a company, part of a self-managed super fund or guarantor of loans.

"You may even need to seek some financial advice," she said.

The starting point for protecting yourself from sexually transmitted debt is to talk about money, which can sound very unromantic at the start of a new relationship when romance is high on the agenda.

"I am a great fan of before we mesh our lives, before we open a joint bank account, before we rent somewhere together, before we do anything that involves 'us', that we need to be looking at each other's finances and having that transparency," Ms Browne said.

"It's not necessarily judgement; it's just about understanding what this person has come into the relationship with and how it is going to affect me."

Ms Browne said by understanding each other's finances and expectations around money right from the outset, couples can make great decisions together.

"Getting a big financial surprise after you've been together for five years will break trust and could break the relationship," she said.