There is nothing like the feeling of outrage, judgment, and – let’s be honest here – genuine interest that comes up whenever anyone starts to talk about physical and spiritual relationships between family members, regardless of how distant their branches on the family tree might be. There is even a fancy word for this sort of inter-family union: consanguinity. Bust that bad boy out in a game of Scrabble, and your victory is assured.

Our cat does not have to worry about consanguinity issues, or any moral or religious judgment from her peers. Her father is also her brother and, we think, her grandfather and cousin, and neither the law nor our cat has any issue with her chequered family history.

With us humans, though, it is a different story. In Australian society, and under Australian law, there are clear limits on what you can and cannot do with your family members, including your attractive cousin, when it comes to things like marriage and the typical consequence of marriage – producing children.

There is a definite religious undertone to these laws, as you would expect given we are talking / writing about marriage. Of course, the law in Australia is not so blatant as to say ‘you cannot marry your cousin because the Lord does not approve of such unions.’ However, our law does say that certain unions between two people, whether physical or emotional, are illegal and leaves it to us to work out the reason why the law says this.

Even if religion does not play a role in the law on marriage, genetics and health sure do. It is clear from science, and by looking at certain royal family members past and present, that the closer two people are genetically the more chance there is of them passing on their crappy recessive genes to their child. This can, and often does, result in birth defects, mental health issues, and the child’s early death from health complications.

As a result, our laws restrict marriage and sexual relations between close family members to prevent this sort of in-breeding and the health consequences it causes. And to keep God happy, I suppose.

You can make all the arguments you like that people should be free to love and marry whomever they chose. I completely agree, as did a majority of Australians in the same-sex marriage postal ‘survey’ of late 2017. But I also accept that, religious and cultural aspects aside, the law does need to say that certain marriages are prohibited, to remind us all that keeping things in the family never ends well, from a genetic point of view.

But enough moralising. You want to know whether, legally, you can marry your cousin.

The answer, in all states and territories of Australia, is a clear ‘yes.’ Under Australia’s marriage laws you can marry anyone in your family, so long as that the person is not:

⁃ your ‘ancestor’ (parent, grandparent, and so on), or your ‘descendent’ (child, grandchild, great grandchild… you get the picture); or

⁃ your brother or your sister (whether of the whole blood or the half-blood, which means the couple has the same mother but a different father / same father but different mother. See the fantastic Simpsons episode ‘Oh Brother, Where Art Thou’ for more details on half-blood siblings).

But before you go out and speak to your aunt and uncle about the dowry for their little prince or princess, you should also keep in mind a few basic legal no-noes when it comes to marriage generally, not just between family members.

You can’t get married if, for example:

⁃ either of the people getting married is, at the time of the marriage, lawfully married to another person. This means that you cannot have multiple husbands or wives at the same time, and you cannot marry your pets or a really sexy car;

⁃ one person in the union has not consented to the marriage or, if they have consented, it is not a ‘real’ consent because they have been forced to say ‘yes’ to marriage out of fear or pressure or blackmail;

⁃ one person consented to the marriage but, through the deception of the other person, believed their partner to be someone completely different (the ‘evil twin pretends to be the good twin’ situation, which I am sure happens all the time in real life);

⁃ one partner does not have the mental capacity to understand the nature and effect of the marriage ceremony or the meaning and consequences of marriage itself (whether this is due to a mental disability or a lack of knowledge of the nature and consequences of marriage under our laws and in Australian society);

⁃ either of the partners is 16 years or older, but under 18, and does not have their parents’ (or guardians’) consent to the marriage; or

⁃ either of the partners is under 16 years of age.

As long as you do not fall foul of any of the above restrictions on marrying your family members, or breach one or more of the basic laws that set out what is a valid marriage, you’re free to marry whomever you like. Including your hot cousin.

Have fun, hope your wedding is wonderful and your cousin-wife or cousin-husband makes you very happy.

Weirdo.