While it is not illegal in Australia to have a wife and a mistress, a husband and a lover, a wife and a lover, a husband and a mistress, or even a few de facto relationships at the same time; it is illegal to be married to more than one person. In the first season of Rake, an Australian television series, criminal lawyer Cleaver Greene brilliantly exposes the hypocrisy of the marriage law when he defends a famous chef accused of bigamy, an offence Greene found outdated. But what is bigamy?
Part VII of the Australian Marriage Act establishes bigamy as a serious offence which could result in 5 years imprisonment. The laws identify two ways to commit bigamy, (1) either a person is already married and goes through a form of marriage with someone else, or (2) a person goes through a form of marriage with someone who is already married. Contrary to polygamous or polyamorous relationships, bigamous marriages involve definite deception. Either one person deceives another by refraining to mention he or she is already married, or the couple (both parties know of the valid marriage) deceives the State.
You may notice that I used a number of terms in the first paragraph to describe different arrangements, amongst them de facto relationships. This is an important distinction because in some cases (mistress and lovers) the parties have not gone through the legal process of marriage, and instead have private understandings. It would be wrong to assume that polygamy (Sister Wives style) is illegal in Australia. In practice, a polygamist who lives with all his “wives” (rarely would we encounter a woman who lives with many husbands) can do so if he only formally marries one of them.
One may ask, just as Greene proposes, why keep bigamy on the books? Especially when Australian law specifies that “a de facto relationship can exist even if one of the persons is legally married to someone else or in another de facto relationship”
If interested in reading more on the difference between polygamy and bigamy check:
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