Jesus christ. And of course it was a woman getting shit on cause the double standard is also rampant. Referring to the post I mentioned, men go to strip clubs, Hooters, etc. to see and get touched by hot women and they definitely talk about wanting to fuck them with their friends but ain't no one ever gonna call that emotionally cheating I guarantee. And if a guy passed out with a woman like that they wouldn't claim cheating they'd tell the gf she was being insecure which is accurate but still BS its only applied to one

People have this idea that FB is just for old folks now but the shitposting groups on there are fantastic lmao that's all I use it for

While having fantasies about whomever would be considered normal, it implies at the very least a challenge to the relationship

because it clarifies how inconsiderate they were to come into this relationship not ready to commit and presumably not even knowing what they want.

It literally does none of those things. If you are in a monogamous relationship and have a simple day dream about someone else from time to time that doesn't mean you're not committed. It's a perfectly normal human thing and if they're not acting on it in anyway that does not change the fact they want a monogamous relationship with you. A fantasy is just that a fantastical imaginary thing that you don't neccesarily want to come true. If I like the job I'm at and have been in it for years but sometimes wonder what it'd be like to choose a different career I'm not inherently suggesting I want to leave my job or I'm not committed to it, it's just a curiosity thing. Or I dream about doing some wild career that I could never actually do like being an astronaut that doesn't change the fact that I absolutely know I want to be in the career I'm in.

depends on being able to exercise some amount of control and discipline over your desires,

By not acting on it at all that is control and discipline. Discipline is not, not having those desires at all.

Thoughts are not actions and you cannot equivocate the two without causing a lot of problems

I would argue that is about extreme monogamy rather than just jealousy because it all stemmed from the idea that your partner should have all their desires met by only you, and should not even have a stray thought about anyone else or they are unfaithful which is different from the kinds of toxic jealousy that might occur in a non-monogamous relationship.

And it was majority of the comments that agreed with them and there were a lot of comments. It wasn't a fringe opinion from a few abusers it was a common sentiment

Yes but those are all common symptoms of unhealthy monogamy. It is absolutely tied to monogamy because it's the idea that anything your partner finds attractive outside of you or if they're not getting every single desire met by just you, is bad, is shameful, is wrong, is unfaithful etc. I specified extremists because no this isn't what all monogamy is like obviously. But because of our often puritanical societies many take it too far like this.

I'm not shaming a life choice I'm shaming unhealthy relationship ideas that lead to bad things and are sometimes borderline abuse. Calling your partner a cheater for having a fantasy is controlling and abusive. You can't police your partners thoughts. I'm not chastising monogamy as a whole I'm chastising something that's not ok the same I would with bad behaviors in non-monogamy

Speaking personally, If I decide I don't want to be with someone who isn't commited to a notion of commitment we agreed on, then yes I have been cheated on.

No you haven't unless they actually did something outside of the agreed upon commitment. Them simply considering the idea of ENM or having a conversation with you about it, and you not wanting that for the relationship isn't cheating it's just realizing you want different things which is ok. If they're no longer wanting the commitment you agreed upon but they didn't pursue anything and one of you walked away that wasn't cheating it was just a breakup. Classifying someone wanting a change in relationship style as cheating is just a way to further demonize ENM folks

I mean the concept is real it's the idea of getting romantically close with someone who isn't your partner outside the boundaries of the relationship. It's become a separate term than just cheating cause many people try to claim if nothing physical happened it doesn't count as cheating which is insane. But yes it does get used incorrectly CONSTANTLY and as a way to demonize your partner for normal thoughts and feelings, considering non-monogamy or just being close with someone you don't like. And I do feel you're right that they often will use it to justify a breakup for simply wanting different things.

You just haven't found the good shitposting groups bud FB is great for that