It's been nearly a week now, and there are things I'd like to say about marriage.

It isn't for everyone. That's not an exhortation or even an instruction. It's a fact, just as relationships aren't for everyone. Some people are better off alone.

I love being married. As our 35th wedding anniversary approaches, I can honestly say my life is happier because I married my husband. That's not just correlation; it's causation.

But of the many engagement parties and weddings I went to back in 1983, not many survived. These were the people who realised there is an overt meaning of marriage – love – but another meaning, too. Yes, it's about love but it's also about compromise.

Every small thing is a compromise as you try to find your joint path. I am yet to find a married couple who remain unchanged since their wedding day. Unless that wedding was last Saturday. For this reason, I say that just because you can get married doesn't mean you should.

However, there is a really good reason to marry. Again, it's not about love. It's about proving your relationship exists, which is much easier to do once you've put a ring on it and signed the marriage licence.

If you marry, you have stronger legal rights. Failed prime minister Tony Abbott is morally wrong about lots of things but he was legally wrong when he said same-sex couples in a settled domestic relationship have exactly the same rights as people who are married.

That's just untrue. It's untrue about same-sex couples and it's untrue about heterosexual couples in de facto relationships. Married couples in dispute never need to prove they are married. De facto couples in dispute must always prove they actually had a relationship.

La Trobe University associate professor Fiona Kelly, a family-law expert, says we were all fooled because of changes to the law nearly 10 years ago.

"We did have new legislation in 2008 to family-law provisions which covered de facto couples and there was lot of fanfare about that," she says.

But the big challenge is this: "There is a hurdle that applies to de facto couples that you still have to prove you are in a relationship, so that becomes significant."

Her research revealed cases of lesbian parents who contested their relationship with their former partners. The biological mother's relationship with the child was not in dispute, but the other parent needed to prove the existence of a de facto relationship to even assert they were a parent of the child. Gay and lesbian family-law disputes between couples in de facto relationships centres on the kids.

Kelly, who researches this area with colleague Hannah Robert, says it's a marked difference to heterosexual couples.

"Heterosexuals fight about property, lesbians fight about children," Kelly says. "If you can disprove the relationship, you can walk away with the child."

So that's only applicable to lesbians? Why should straight couples worry about this?

Kelly searched for a similar proposition among heterosexual couples. She found only one, where the child was the result of donor semen, compared to 24 cases of contested parent status over the same period. The mother lost her case against her former husband, but non-biological lesbian parents don't have the same success in claiming parenthood.

And there is much more to reckon with, in terms of proof.

A lawyer at LegalVision, Lianne Tan, says: "Section 4AA of the Family Law Act specifies the circumstances a court may look at in defining a de facto relationship. They include the duration of the relationship, the nature and extent of cohabitation, the existence of a sexual relationship, the degree of financial dependence, ownership of property, degree of mutual commitment to each other and shared life, whether a de facto relationship was registered and any care of support for children."

None of that matters if you are married. Marriage is apparently proof enough.

So should you get married? How important is it to clear up your legal position?

There's a lot more to relationships than just your legal position, and I'm confident the gay and lesbian community is all over that side of it. They struggled with oppression for centuries and this acceptance of same-sex marriage is at least one burden less.

And for some it is a real burden. I note that The Daily Telegraph decided last week to commemorate the historic decision by using some outdated popular culture reference to a TV show most of us have never seen. The newspaper's point was that marriage is miserable, especially for men.

But the research tells a different story. Married men are much happier than married women. Marriage is what you make of it.

For most of the divorces in my cohort, there wasn't anything particularly dramatic, just the realisation that getting married is amazing fun but staying married requires the kind of work that staying fit requires. It can be rewarding; it can also be draining. It requires constant compromise and never-ending negotiation.

But at least you need something in writing if it all goes horribly wrong.

Jenna Price is a Fairfax columnist and an academic at the University of Technology Sydney.

Twitter: @JennaPrice

Facebook: JennaPriceJournalist