Those are some good points but my confusion comes from the fact that even after he married this one chick.
Competing instincts. The desire for sex is irrational, not logical. The desire for a lifetime female companion is irrational, not logical. Both instincts.
Because of his status, he COULD manage to have both for a while. Satisfying TWO but seemingly OPPOSITE instincts.
Like if you were to go to the gym, take off your shirt and see girls respond to your six pack. Your INSTINCTS are telling you to improve your six pack so you can get more attention.
But your OTHER INSTINCTS are telling you shove cheeseburgers in your face.
Having hunter-gatherer instincts in a modern, post agricultural, post technological world causes all kinds of problems and mismatches.
If that same character lived a few hundred before, it would have been SOCIALLY ACCEPTABLE to have a wife, and all kinds of girls on the side.
Check out Marco Polo on Netflix for a pretty accurate description. Kublai Khan had a loyal wife who HELPED HIM to bang all of his young stable of slave girls.
In fact, that's probably the IDEAL SITUATION for most men. A loyal, faithful wife who helps you build your empire
which includes having a tons of side girls.
Some evolutionary psychologists argue this is the PRIME REASON all men crave power. Power allows for a loyal wife AND massive sex with new girls every day.
Unfortunately, the Union of Betas has outlawed that behavior.
A very interesting theory (in Matt Ridley's Red Queen) is that for about a thousand years, the SECOND BORN sons of wealthy families who didn't stand to inherit anything joined the church and slowly changed the rules so that ONE MAN could only get ONE WOMAN, as well as make it harder to marry your cousin to keep the wealth in the family.
A thousand year COLD WAR between the Church and the Landowners.
Landowners = Rich Alphas
Church = Butt Hurt Betas