Adultery has been classed as a low-level criminal offence - known as a misdemeanour - in the state of New York since 1907.

Such laws were traditionally introduced in states across the US to reduce the number of divorces at a time when a cheating spouse was the only way to secure a legal split.

However, only about a dozen people have been charged in New York since 1972, with the last more than a decade ago.

And of those cases, just five have netted convictions, according to New York assemblyman Charles Lavine, who has sponsored a bill to repeal the seldom-used law.

"It just makes no sense whatsoever, and we've come a long way since intimate relationships between consenting adults are considered immoral," he said.

"It's a joke. This law was someone's expression of moral outrage."

Katharine Silbaugh, a law professor at Boston University who co-authored the book "A Guide to America's Sex Laws", said adultery bans were aimed at punishing women.

"Let's just say this: patriarchy," she said.

The bill to scrap the adultery ban has already passed the state assembly and is expected to soon pass the state senate, before it can move to the governor's office for a signature.

How the law has been used since its creation

Just a few weeks after the law went into effect in 1907, a married man and a 25-year-old woman became the first people arrested after the man's wife sued for divorce, according to a New York Times article from the time.

The last adultery charge in New York appears to have been filed in 2010 against a woman who was caught engaging in a sex act in a public park.

However, the case was later dropped as part of a plea deal.

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The law was almost scrapped in the 1960s after a panel tasked with updating New York's criminal laws found the adultery ban was practically impossible to enforce.

However, while the proposal was initially accepted in the state assembly, the chamber restored it after a politician argued scrapping the bill could give the impression that the state was endorsing infidelity, according to a New York Times article from 1965.

Most states in the US that still have adultery laws classify them as misdemeanours - a type of low-level offence.

However, Oklahoma, Wisconsin, and Michigan treat adultery as a much more serious type of offence, known as a felony.

Several states, including Colorado and New Hampshire, have moved to repeal their adultery laws, using similar arguments to those being used in New York.