In the years before the colonialists came to Igboland, for men, a woman's older age was not a factor in choosing her for a wife or even a lover. Young men freely took over widows, even those of own dead fathers (apart from own mothers of course) to marry, or simply continue raising and making children by the women. Her being older was not a factor -at all.

But in the binary marriage system that dominates our part of the world today, such relationship is now at a disadvantage because a man now has only one chance to form a family. Also, the older woman with whom he may have fallen in love may not be of childbearing age, or she may be in her twilight reproductive years. This tends to force men to abandon older women lovers, or widows they should have married, to marry younger ones for the purpose of having children; but then still retain the sexual relationship with the older lovers in the secret world of adultery, or fornication. Hypocrisy has continued to define the marriage system that forces a man to marry only one wife, and the many instances of men (or women) cheating on their spouses continue to prove this point. Society has almost become normalized to the idea of infidelity, or serial monogamy, provided that these all exist within the bounds defined by law. In other words, law has replaced common sense and morality.

A committed observer would notice that the lies and hypocrisy that define contemporary marriage are more dangerous to the goals of keeping the seventh commandment than anything else. In an effort to create a utopian one-man one-woman world (which is not mandated biblically by any stretch), a dystopian society of serial divorces and broken homes has been created, and this manifest through increased clandestine sex, wickedness, and selfishness.

In pre-European Igboland, a man married according to natural realities, not according to some fables and unproven narratives. For instance, if a man impregnated a woman, regardless of her age, tradition demanded that he performed marriage rites to take her home as wife. As long as the woman was a willing participant in the sexual acts that led to the pregnancy, she was expected to marry the man who impregnated her. She was not bound to do so, but unless she planned to have a baby in her father's house as agreed by the family, she was expected to go with the man that impregnated her. If the man repeated such act one thousand times, he got one thousand wives. Simple. The only barrier was if the woman turned down his marriage proposal for whatever reason; or if the couples were too close genetically, like cousins and siblings; or in cases of parental incest; or peoples barred from marrying freely for ritualistic or spiritual reasons, and whatever isolated (or ostracized) group. Such a marriage would also not be possible if the woman was already married; in that case any child resulting from such encounter would automatically belong to the woman's legal husband (the man who performed the marriage rites to have her as wife).

Outside these, everyone was free to marry, or be lovers, in Igboland. It was not a statutory matter (there was no state anyway). It was a local traditional matter. Variations existed in different Igbo clans, but the practices were largely the same. Clans adopted what worked for them, not what was forced on them by some higher human authority.

Women were not allowed to have more than one husband in Igboland because the ancestral cultural custodians felt that it was not necessary, probably because a woman was allowed to keep “Iko” or lover who was not her husband, if she so wanted. The Iko was known to everyone including the husband who gave consent by entering into a covenant with the Iko man. The covenant was necessary to ensure that the Iko never endangered the woman's husband or the woman's family.

A man married according to his natural physical abilities and social status; while a woman lived to her fullest potential regardless of her husband's physical and economic abilities.
The relationship wasn't solely for economic reasons, or solely for social reasons; it was a combination of both, and more. Women did not depend on the men for spousal support or sustenance. Women owned farms and domestic animals and traded the products at will.
Therefore, if a love relationship developed between a young man and an older woman, the love relationship developed naturally, and ended naturally, without anyone feeling cheated, or the type of sense of loss that leads to adverse reactions including homicide. Igbo marriage institution separated “love” from marriage because it was understood that love is ephemeral. Marriage, even when initiated from love or attraction, simply continued long after love had exhausted in the marriage, thereby allowing families to remain whole and unbroken. Unbroken home and strong family was the backbone of pre-European Igbo society.

A relevant comparative anecdote is a news in one of the online news sites about a couple (non-African) who will divorce because the couple finally decided it was time to tell everyone (including their children) that the man is gay. The couple had been together for 17 years, and the woman had known about the man's sexuality before the couple tied the knot. What is baffling, is that they decided to divorce after all these years. Now the children will have to deal with parents living apart -basically their family is now broken. This, because of “love” shifting grounds in the family. Love (more like lust) is not, cannot, and should never be enough to sustain a family past one generation. Therefore it is sensible to demand more than love at the onset of marriage. In fact it is more desirable for a couple to undertake a complete self examination before deciding to tie the knot.

One is tempted to place the old Igbo marriage system side by side the contemporary Greco-Roman version to see which supports the human family better.
Without any doubt, the old Igbo marriage was more stable and equitable because it operated on the basis of holistic, collective, and reciprocal morality.

Present day humans tend to lack empathy, and are driven purely by selfish instincts.

Unlike contemporary marriage system, clandestine sex and illegitimate offspring situations were very rare in old Igboland. For a woman to have an illegitimate child, she really had to reject all available institutions of correction and rectitude available to her. Also, were a woman not able to have a child, it simply meant that she was totally barren and could never conceive. Rape was an abomination, and hence very rare, because most men had avenues for venting sexual pressure.

Whether such a marriage system or even sexual institution can ever exist again in the Igboland swallowed up by colonial and neo-colonial culture, is an open question.

-Nigerialog.com

But these day it all seems so far fetched and almost scandalous.
It wasn't like that before.

So, it has tey?!

Though the op used Igbo culture as a case study, varying versions of it applied to other Nigerian ethnic groups.

Our problem is criminalizing our cultural norms in preference to European ones.

These days what we see are cases like this:

A Hollywood man fatally beat his wife with a pipe wrench after learning she was pregnant with her boyfriend’s baby, police said.

Claude Sejour, 49, then called 911 to report the crime.

“I did it. I finished her and called the police and went outside,” he said to the arriving officers, according to a report. He was wearing a bloodstained white button-down shirt and had blood on his hands and cheek, the report said.

“I’m not crazy,” he told officers, according to the report.

As his wife, Marie Joseph, 40, lay dying in her bed, her 17-year-old daughter tried to wake her, a neighbor told police.

Sejour, who did not appear to have a criminal record, was being held without bond in Broward’s main jail Thursday on a murder charge.

The deadly encounter unfolded just before 10 p.m. Wednesday inside their home in the 5900 block of Thomas Street. In addition to the daughter, the couple’s three other children, 14, 12 and 4, were all home at the time, police said.

Sejour called 911 and first told a dispatcher that he was going to kill his wife. Then he said he did kill her and would wait outside.

Meanwhile, another call came in, this one from Sejour’s neighbor, Alvaro Garcia, according to the police report.

Garcia later told police he heard screaming and saw Sejour on the phone. Sejour, he told police, waved him over and then told him he had killed his wife. Garcia told officers that Sejour said he had just learned his wife was pregnant with another man’s baby and had “disrespected him,” the officer wrote.

Garcia said he went into the house to find the couple’s oldest daughter on the bed, trying to wake her mother. He checked for a pulse and realized she had died, according to the report.

An officer found Joseph lying in bed in a sports bra and blue pajama pants.

“I observed severe trauma to her right eye, left cheek, forehead and on the top of her head,” the officer wrote, adding that there was blood on the wall above the victim’s head. “There was a red pipe wrench which appeared to have traces of what appeared to be blood.”

Sejour was then taken to the police station for questioning. After being read his rights, police said, he told police, in his native Creole, that he had gotten into a fight with her because she was on the phone with her boyfriend and her boyfriend said she was pregnant, according to the report.

“Sejour felt she wasn’t taking care of him or their children as a wife should do,” the officer wrote. “He stated he didn’t mean to kill her but he was angry about the man and the baby.”

https://www.nigerialog.com/family/man-beats-wife-to-death-after-learning-she-was-having-another-mans-baby-police/

Clearly what the woman did was bad, but should she have been bludgeoned to death for it?