The issue of same sex marriage has actually dominated conversation across the globe over the years, with no concrete and consensus agreement on what it should be. Some other countries have either passed laws in favour of practice of same sex marriage and relationship, some others have laws against it.
Meanwhile, in all of these issues, there’s a certain tribe in Nigeria, the Igbo people, who has a culture looking exactly like the same sex marriage. But in this situation, it is basically between two women, and doesn’t include the male gender.
In this kind of marriage, a woman, precisely a widow who has either entered her menopause or was previously married and the husband died without them having child/children, then she is permitted by custom of the Igbo people to go ahead and marry a woman, mostly younger women who are still in their reproductive age. The essence is for the newly married woman bear children, mostly male children, to preserve the family lineage or continuity.
Before she embarks on the mission of marrying another woman, the older woman must first inform the Umunna about that, and with their consent. Then they goes with her to the family of the woman they intend marrying for her, performing necessary traditional marital rites including paying of the woman’s bride price.
Normally, the widow would prefer marrying a woman who already has children outside wedlock, mostly male children, who then becomes her children upon marrying their mother by fulfilling all traditional rites, most importantly the bride price, because in Igboland only the payment of bride price validates your fatherhood or right to own the children a woman has for you.
On the other hand, after contracting the marriage, the widow who married the woman is often given some sort of special honour and place in the male folds. The woman she married is now free to go about meeting other men, for the sake of getting pregnant and children subsequently, for the family she’s married into.
Any child she bears throughout her life, except the marriage was later dissolved, automatically belongs to the family she’s married into. The reason she’s allowed to go out meeting men is simply because the marriage of woman to woman is non sexual, as such, the two women can never have sexual business, as it is an abomination in the land, and not what that tradition stands for.
Frankly, the culture or tradition as you may put it, has actually helped in preserving the lineage of many families in Igbo land, and I even have one in my own village, the only male child born into the family is the only person continuing the family’s lineage.
Note, that this very tradition is still in existence in most part of Igboland, and I heard it is equally practiced in several other parts of Nigeria, especially in the southern region.