Ok..let me present you some ideas regarding the title, a personal point of view and then let's take it to the next level.
Perpetuation of the species: One man, one woman. Leave a chance to the others to mate and replicate.
Defending the territory: he is my man, she is my woman.
A modern definition of cheating: since we are so much into love and trust, why do we consider cheating when our lover has sex with other people, even if we are informed it is JUST sex and NO feelings? (for example, in a VERY long distance relationship)?
Especially for men: Why do we feel guilty about cheating? Who told us to feel guilty? Who took our freedom away?
Especially for women: Why do you feel guilty about making the first move? Is it prejudice, is it habit, is it the same fear of rejection that men HATE? (now you should understand how hard it is for most of us to approach you )
From the tribal approach, have we been brainwashed in order so more women can pass along their genes? Have we becomed SO feminine..not to hurt a woman?
All of us have lessons to learn in life and love. For a woman, the challenge is not to find a man, but to keep him.
Why shouldn't a woman learn also from break ups and broken hearts? Is this kind of learning only for men? Does a woman think "Hey, you're a man, you'll get over it?" - without knowing that most men have become SO emotional and sensitive?
Please share here your point of view and your insights.
My point of view and a small personal history:
At the beginning, I used to be caring and sensitive. The shy me couldn't even dump a girl on my first relationship, because this would have hurt her feelings.
Later, I started dating multiple girls and women. Some of them knew, some didn't. I really enjoyed it, as each of them made me somehow happy and showed me a different experience of love.
Today, and this is perhaps my strongest advice, when I am in a deep and magic love relationship, I stopped dating more women; as I said somewhere else, I owe it to myself and to my dreams.
What a coincidence, this translates also in the fact that all the women out there are available for more men, since I as a male have stopped hunting.
When you really care about the relationship you are in, when it really promises a lot, when it makes you really happy, then consider remaining "faithful", as you owe it to yourself more than you owe it to his or her feelings.
Meanwhile, regardless if you are a man or a woman, make your new found lover understand that a "faithful" lover is to be earned, not taken for granted. Put a price on your feelings, on your focus, on your time and on your personal space.
If your love life has been incredible until today, perhaps you can ignore this ideas. If not, what have you got to lose?
That's what I think.
NOW...what do YOU think about these realities?