Not everyone has an impulse to cheat or a desire to cheat. Some are happier in monogamous relationships, others are happier in something polyamorous or open. There is no wrong way to build your close relationships as long as all involved want the same thing.

Natural doesn't supercede consent. Again, if everyone is OK with an open relationship its fine, but condoms aren't natural and its clear that removing a condom without consent just because that is more natural isn't ok.

I acknowledge that societal dating pressures exist. That being said, claiming that individual preferences are illusionary trivializes individual preferences altogether. Whether or not the preferences comes from a societal pressure, doesn't mean its invalid. If anything, believing otherwise can be dangerous. For instance, if a woman doesn't wants kids, that's not necessarily a bad thing. Claiming that they're wrong because there's a biological desire for humans to reproduce would be obnoxious.

That's all to highlight that others individual preferences should be respected. This includes both monogamous and non-monogamous preferences.

As for the comparison between fighting and romance I made, it wasn't to claim that these two things are similar in substance, rather I was saying they're similar in origin.

I think you need to preface this by saying "You have no desire for monogamous relations" but you absolutely can not say "All people want to be polyamorous". Only some people do, and it certainly would be nice if they were not pressured into something that doesn't work for them.