I'm a ...

...serial monogamist.

"Monogamous for life" or "pair-bonded" for life means something very different in the year 2003, as opposed to over most of our evolutionary history. Part of the reason is that our comparatively long lifespans are a new phenomenon in the developed world, the creation of good sanitation and nutrition, partial control of infectious diseases, and better medicines. Until approximately the 19th century, a really old man or woman was usually someone in their forties.

So historically, a lifelong monogamous relationship only had to last twenty years or so, long enough to raise the children. Probably the existence of this board is testimony to how hard it is to faithfully sustain those relationships beyond twenty years, at least for men.

In any event, I'm not too sure about your statement that humans have always tended to monogamy. Epidemiologists are always complaining how hard it is to track STD's, largely because people lie all the time about sex - to themselves as well as to others. And it is the STD's that tell you what people are really doing sexually.

Personally I don't believe there's a "meant to be." Some people are monogamous and some are not - possibly just as some are blood type O and some are not. One size and one color doesn't fit all. Certainly those who aren't monogamous will then postulate that's monogamy isn't "natural." For me monogamy was the right thing (until my wife left after 24 years) but I realize it's not for everyone.

The reasons are that males want lots of offspring, females want to ensure survival of all the offspring.  Those are the biological imperatives, with no regard for society, culture, religion, etc. That being said, we sure are way past just behaving according to programming.  Successful societies try to ensure quality child rearing environments, thus monogamy... which is undoubtedly a good way to make kids feel secure.  I know mine are pretty unhappy with having their Dad living in a different house than they are. So am I by the way.

So, as far as sex goes, a man who has a wife that enjoys sex, and even enjoys things like role playing, fantasies, lots of variety in positions, approaches, basically open minded, will probably have the best of both worlds, at least if he wants to raise happy kids.  if no kids are involved, then all bets are off.  And I guess a liberated woman wants all the same sexual excitement, so guys, we have to buy cowboy hats, boots, fireman outfits, the whole bit, if we want to be fair about this.  Hey if she's a fox and likes heels and stockings, why shouldn't I wear a football helmet or whatever the fuck her fantasy is, right?

There is a historical bend toward male possession of the famale... but a male would possess more than one if he could handle it.... right? Right.

I think Chris Rock nailed it "a man is as faithful as his options." LOL

If you believe in evolution humans and our ancestors have never been monogamous. Both male and female are not monogamous. Males have the instinct to have sex with as many women as possible, while women try and find the best male to be the father of their child and the best male to father their child. Not always the same person.

Examples of women not being monogamous are:
Studies have shown that 12-15% of children are not related to the male their mother has led them to believe is their father.

And

Studies also show that in modern western society young women tend to time their nights out away from their male partner, with when they are ovulating. i.e when she’s most likely to get pregnant.

We are not meant to have on partner for life, and if say, one hundred thousand years ago, all humans had only stuck to one partner, would any of us be here? Who knows maybe humans might not have survived? Maybe there have been human speices that did practice monogamy, and then became extinct?