What is your opinion on having an open marriage?

Lately it seems that I am hearing a lot of women promoting open marriage and polymory in their marriage. I can't wrap my head around how this is okay with people, especially with men. Who is the father to her kids? Who pays the child support? In my days , thing of value doesn't get shared with other people, this is a sick world people are making for their kids to live in. What is the reason to get married if you want a relationship with someone else. I am ready to get off this rock we call earth. People put no value on relationships and marriage anymore. From what I have seen, it seems to be more of the women pushing for this than men. Women can find a man to have sex with so easy but men have to work hard to get a woman to have sex with him. This one of the main reasons I think people should stop getting married or into a relationship. What is your opinion on this subject.

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Should both get sterilized before starting this kind of lifestyle?
What is your opinion on having an open marriage?
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