If you are a guy, whether you accept it or not you are in an "open relationship."

Accepting the RP maxim, "she was never yours, it was just your turn" is one of the huge steps off the precipice that guys take after swallowing the pill. It's one of the things that really rips you up and ignites the initial anger phase.

Once you settle down a bit, you begin to accept that the essence of hypergamy is that if you are not continually developing into a more awesome version of yourself, she will leave you for a guy who seems like a low-rent douchebag, because tingles or GTFO. It's not personal, as /u/OmLaLa put so brilliantly in his "Such is my Nature" post, it's just how she's wired.

Some couples try to fight this by agreeing to accept their companion going out and fucking other people. When a man indiscreetly fucks other women, it's called "toleration" or just being rich. When a woman fucks other men, it's called an "open relationship," which is basically when the guy keeps providing for a woman while she is test drives her next step up.

The fundamental error in the concept of most open relationships is to believe that the "freedom" to scratch a sexual itch can quench the hypergamous urge. It doesn't go away. You are either her best option, or you aren't. A rare enlightened few are able use the openness to reaffirm the continual choice they make about each other. Achieving abundance means you can let a woman go, and be happy for her because she has made a choice that is consistent with her nature. But for most of us, that's some pretty zen shit.

The reality is, her nature means that when you are no longer her best option, you evaporate in a puff of dried up tingle-dust. Just as you can't feel the pain you inflict, nor can she. So as Blake wrote, "the cut worm forgives the plow." When she says she doesn't want to hurt a guy, what she really means is that she doesn't want to lose the guy. If you are that guy, it's because you have made it worth it for her to stay by being (not merely providing) something she can't find with less effort elsewhere. The only thing you can be with any guarantee of uniqueness is you as your most raw, basic, and honest self. She can get money, power, bling, sex, and undying love like hailing a cab, so seriously, fuck it, just do you.

She's a human animal, she's going to do what (read:whom) she wants, and if you two are monogamous, it's because it is you she wants. A "relationship" is not the trappings of an agreement, some principled inference, or a thing you make, it is the effect of you choosing each other - and that effect is how you relate.

Whether either of you accept it or not, hypergamous nature means that your relationship is open.

Part of being a man is accepting that when even the most precious things in your life change and pass, as they must, you remain, persist, and grow. That is why stoicism has been the go-to philosophy of men for thousands of years and Asian philosophies are so concerned with attachments.

Formal open relationships seem like a civilized and rational alternative to breaking up, but you are already in one, and it's the belief that rules apply that will make it end in tears. Man plans and God laughs. The solution is this: Don't structure "open relationships"; relate openly with self-acceptance, abundance, stoicism, and appreciate each woman for what she is, and if you are still not her best option, I guarantee you will at least be your own.

edit: cleanup.