What makes up a "domestic relationship" between a man and woman? Certainly not "merely spending weekends together or a one-night stand," according to India's Supreme Court. As if this truism was not enough, two senior judges remarked: "If a man has a keep [a crude term for a mistress] whom he maintains financially and uses mainly for sexual purpose or as a servant it would not in our opinion be a relationship in the nature of marriage."

The court got worked up over the definition of a "domestic relationship" - critics frowned at the language it had used in defining a mistress - after a school teacher appealed against a family court judgement asking him to pay 500 rupees ($11) maintenance money a month to a woman, with whom he had allegedly had an affair. The woman says she married the teacher. The teacher denies it, and says he was already married when he met her. Now the courts have to decide whether the teacher's relationship with the woman was a "domestic relationship" and whether she was eligible for maintenance.

That was not all. The court hinted that a domestic relationship, something akin to marriage even, would possibly suffice to define a "domestic relationship". In doing so, the judges even referred to some of the common tenets of the Common Law Marriage - borrowing from Wikipedia - followed in countries where such arrangements have legal status: the two must be of legal age of marriage and must have "voluntarily cohabited and held themselves out to the world as spouses for a significant period of time", among other things.

In a country where talking about sex and relationships largely remains taboo, it is interesting to see India's highest court debating relationship outside marriage. Marriage in India is intimately tied to sexuality. "It is almost if marriage laws exist to legalise sexuality, punish any deviation from legally sanctioned rules and, of course, to legitimise the children of the marriage," says lawyer Indira Jaisingh. The fact that the courts are according legitimacy to relationships outside marriage is welcome and shows they may be facing up to realities.

Earlier this year, the Supreme Court ruled that a man and woman living together without marriage was not an offence, as some believed. "When two adults want to live together what is the offence? Does it amount to an offence?" the judges wondered. The observation was in response to a petition filed by an actress who had been accused in 22 criminal cases after she allegedly endorsed pre-marital sex in media interviews. Interestingly, the judges even invoked Krishna, the God of love, and his consort, Radha, who, according to legend, lived together. Last year, the court ruled that a man demanding a dowry from his partner in a live-in relationship could also be prosecuted under the country's anti-dowry laws.

The Supreme Court is only taking note of the fact that sexual mores and attitudes are changing. For a society that gave birth to some of the greatest texts on erotica - including the Kamasutra - Indians have long been squeamish about talking about sex and relationships. By contrast, India's classic erotic texts are explicit, matter of fact and non-judgemental about sex and relationships. The country has a highly evolved tradition in erotic temple sculptures and erotic texts on palm leaf. Many historians believe that the arrival of evangelical British colonials to cleanse the "dark land of heathens" dealt a blow to a "vision of the world that accommodated desire with such intensity and dignity". Later, Mahatma Gandhi himself opted for celibacy at the age of 36, telling the world that sexuality was "poisonous" and passion a "distortion". Equating sex with sin and desire with guilt has led to what social commentators say is a climate of "hypocritical morality".