It's not the desire to have multiple partners that is an evil, it's the lying about it that is. I am also 100% in support of anyone on here who has suffered this level of deception. Especially to the people who are left literally holding the baby. You are left feeling that your cheating ex has robbed you of your past, your present and your future.
However the lying of course comes from a fundamentally cowardly place of either:
A - You have no intention of ending your primary relationship, but you want to screw around.
B - You meet someone you think might potentially be better for you, but you don't want to end your current relationship.
A can of course progress into B, but even if not what they both have in common is a total lack of respect for your current partner. Either keeping them around as an emotional safety net (cowardly), or putting them at risk of STDs (disgusting). Even if you claim you love them the simple truth is you are prioritising yourself 100% over your partner. That is not an act love.
What confuses me is why communication and honesty haven't caused a couple to seek to work past what may have started out as a resolvable issue, but sits there and stews until it breaks the whole.
If I were to hazard a guess, nobody likes to see themselves as the villain (unless they are a sociopath and simply do not care), and start telling themselves little fibs and twisting things at first in a subtle way to justify selfish acts.
As far as feminism is concerned women are at a considerable disadvantage here, as there is a vulnerability whilst pregnant, they are usually the ones left with care of children after splits, as people have mentioned there is a prejudice against women who have had children that simply doesn't exist for us men, women in the main earn less. The tragedy here is this all doesn't have to be the case. We need feminism until these imbalances are fixed.
I'd also like to challenge the view that the status quo benefits men. In reality it doesn't. As a man I don't want a long term partner who is with me merely because society traps her there. That is not love. I also don't want a woman in my life I have to build a life for, I want someone to build a life with. I don't think that is unrealistic, and although I'm not on board with every feminist principle (perhaps down to my own lack of comprehension of it, I've come to it relatively recently). I believe 100% it moves society in the right direction, and should my ideal partnership elude me in my lifetime, perhaps if society moves to a better place it will not for my son when he comes of age.
Don't misunderstand me either I don't place women on a pedestal, I've been lied to in past relationships, but this doesn't make all women liars, just as it doesn't make all men liars when I read about the atrocious ways some women have been treated on here.
Wether people believe in monogamy it becomes less significant, once people start being honest with first themselves, and then once they find the strength the people they love.