Every stride has a widespread new ideology and impression. One of those is cohabitation, which means

"Live-in-Relationship". The concept is not new, it originated in the 16th century from the Latin word 'cohabitate'. In Western countries, cohabitation has been prevalent since the 20th century but in the 21st century Indian urban society also influenced the idea of live-in in metropolitan cities like Delhi, Mumbai, Chennai, Bangalore etc.

Mainly in small towns, people having conservative and stereotyped minds don't know much about cohabitation but are still living in live-in relationships for a long time. What is cohabitation or live in? Cohabitation is an arrangement in which two people live together but are not married. They are frequently involved in long-term or permanent romantic or sexually intimate relationships. Cohabitation, in a broader sense, refers to any number of people living together.

After the legalization of homosexual marriage. Same sex people also live-in together and it's not an offence now. In the case of S. Khushboo v. Kanniammal (2010), the Supreme Court of India for the first time recognized live-in relationships as "domestic relationships" protected under the Protection of Women from Domestic Violence Act, 2005 ("DV Act").[1][2] The Court ruled that a live-in relationship falls under the ambit of the right to life enshrined in Article 21 of the Indian Constitution.[3]

In ancient Hinduism, the concept of cohabitation without marriage exists as the name of (Mitru Sambandh'). This "secret" was revealed for about 4000 years ago by an ancient Hindu prince named Yudhishtira. In the Aranya Parva of the great epic, the Mahabharata, there is an episode known as Yaksha Prashna.

One of the questions the Yaksha posed to Yudhishtira was "kimsvinmitramgrhesatah?" (Who is a householder's friend?) To which the prince responded "bhaaryaamitramgrhesatah," or a householder's friend is his spouse. One of the famous examples of live-in in ancient times is of the king Dushyant and Shukantala. Both were in love and had a son who was none other than King Bharat whose name this country India is. A Live-in relationship is not an offence but is still not socially and morally acceptable by society.

Vedic perspective on cohabitation
Cohabitation is not new for us in the wheel of time when other countries were not civilised properly in India previously known as Aryavarta, people living there were familiar with cohabitation also known as a live-in relationship which people then called Gandharva vivah, mitru sambandh.

the first description was found in Apastamba Grhyasutra of ancient India where eight types of marriages were explained and one of them was "Gandharva vivah" where girls were allowed to freely choose a partner without the consent of anybody and both parties could live together without any marriage rituals, based of consent and love for each other.

According to Riga
The most commonly described marriage type in Rig Vedic opinions and classical literature was Gandharva, in which the bride and groom could meet each other in their ordinary life, or places such as regional festivals and fairs, began to enjoy each other's company and could decide to be together. Their kins generally used to be approved of their freedom of choice and mutual attraction.

According to a passage in the Atharvaveda, parents usually left their daughter free to choose her lover and directly encouraged her to be forward in love affairs. In Atharvaveda, a famous term is used "Pativedanam" which means a girl after post-puberty is free to choose her partner. According to the divine being Narada Muni ".

It also claims that if a woman is forced to marry against her will or is prevented from marrying the man of her choice, her curse is more sinful than Gohatya and will destroy the oppressor's ability to attain Moksha". o Great sage Baudhayana claims that this is the best type of marriage as it is based on love and free will.

Manu argued that Gandharva marriage is the most suitable form of marriage, and very rarely it is not; he goes on to say that Gandharva marriage is best suited for priests, warriors, military personnel, administrators, nobility, and rulers.[4] Later on, Why did the live-in relationship concept collapse?

Some justifications for declining are:
Rapidly increased control of their children by parents like wealth, cattle and property type. the Rise of a new concept of child marriage in the Vedic era the age for girl marriage is 16 years but later on, girl marriage is prevalent at the tender age of 12 years. Central Asia and Egypt invaders also influenced Islamic ideology in India which was against the idea of Gandharva vivah (live-in).

Islamic philosophy rejects the theory of cohabitation, according to sharia law live-in is against the order of Allah and those who do this act are sinners.

Landmark Judgements that changed the dynamics of cohabitation in India
In the case of D. Velusamy v D. Patchaiammal. the Honourable Supreme Court ruled that:

The individuals must present themselves to the public as being comparable to spouses. To get married, they must be of legal age. They must also meet all other requirements for a valid marriage, including being single. They had to have lived together voluntarily and pretended to be spouses to the outside world for a considerable amount of time.[5]

In the case of Madhu Bala v. State of Uttarakhand and others, the respective court said that it is legal to have consensual cohabitation between two individuals of the same sex couple.[6]

The Supreme Court of India in the case of S. Khushboo vs Kanniammal said that Adults engaging in voluntary sexual relationships outside of marriage are not prohibited by law, so doing so does not break the law.7

The Court also cited the 2006 decision of Lata Singh v. State of U.P. & Others, in which the Court ruled that a major girl is free to live or marry as she pleases. The Court further declared that the accused had not broken any laws and that the current case was an abuse of the legal system and administrative procedures.[7]

Conclusion
At the time India got Independence it was having 1.5% GDP and about 17% of literacy rate. The population living in our society were not socially and mentally as developed to accept this concept palatably. They considered it as a sheer unwelcome concept that could pollute their pious environment. But then too it used to happen, the difference is it wasn't that common or general.

Many zamindars and people of the elite class were involved in live-in relationships. But, widely an Indian perspective it was taboo at the time. Whereas, the younger generation has substantially welcomed this concept as compliance with their Fundamental Right to life and liberty. Constitution itself allows as far as Fundamental Rights are concerned then who are you and I to judge and find it obtrusive?

Nearly half of kids born in Britain today are to unmarried parents. In Scotland in 2012, the percentage increased to 51.3% from 47.3% in 2011. It is being said that, by 2016, the majority of births in the UK are predicted to be to unmarried parents. It would be quite safe to say that it's neither completely wrong nor right rather it acts as a mediocre between right and wrong.

End-Notes:

1. S. Khushboo v. Kanniammal, (2010) 5 SCC 600
2. Domestic Violence Act, 2005 (Act 43 of 2006)
3. Constitution of India 1950, Art 21
4. Johann Jakob Meyer, Sexual life in ancient India: a study in the comparative history of Indian culture, Motilal Banarsidass Publishers, 1989, p. 90, ISBN 978-81-208-0638-2
5. D. Velusamy v. D. Patchaiammal, (2010) 10 SCC 469
6. Madhu Bala v. State of Uttarakhand, 2020 SCC OnLine Utt 276
7. Lata Singh v. State of U.P., (2006) 5 SCC 475