The most irritating of man's invention - marriage!!

Yes... I call it 'invention' for various reasons. Institution.. nah.. Man invented this relationship, for various stupid reasons he that he thought were valid. I mean when he found that the woman was.. sorry "IS" better than him in various ways, he decided to use the ultimate weapon... and invented marriage. Someone he has to wipe and clean after him, to cook for him, to look after his sexual needs and many such things, he called it a wife. Okay, my apologies to some of the 'womanized' men... but hey after so many millenia of being on the other side, u guys asked for it.
Why can't one live without having the name tag and a tagger for life? I have seen, am still seeing around me so many 'failed' marriages. Yet both the human beings go on with their life, dragging the corpse of a dead relationship behind them or carry it over their heads. It is wrong. Everyone has a right to be happy. But then each one has his own thinking. There are couples so much in love with each other, it makes me want to puke! And I have seen many of such love birds flying off with other crows. Then why? Human beings are radical beings. Each one has an ever changing environment where we are adapting at the rate that we ourselves done know. But still we have this notion that stability makes us human being and we have made our relationship the scale with which we measure that stability so that we can prove to each other that we are humans. And the best relationship, that we even celebrate, is marriage. How can two minds be one? Okay forget the spiritualistic nonsense that we are all one and part of the one. Even if we take this logic into context, we don't need marriage then, do we?
We are happy, we say that. Why? How?
Marriage is between two people who want to make each other happy.. my best friend said that. When I asked was the making happy part out of free will or was it compromise or were both people supposed to be happy on a compromise? Or as it usually happens, SACRIFICE!!
I still have to get an answer.
And the greatest of it all is the sexual exclusivity. In this time, when 80% or more of the married population spends 8 to 10 hrs of the waking time in office, in proximity of other prospective mates.. :) .. what about it then?