You did not specify, you did not even mention unethical non-monogamy.
Non-monogamy is a feminist action, and my goal is to persuade you to engage in it.
No narrowing it down.
In monogamous relationships, often, sex is an expectation, as are other more nebulous things such as emotional labor. If it’s not occurring, the relationship may be considered dysfunctional. In non-monogamous relationships, this isn’t the case.
No specification, just“in non-monogamous relationships”, no narrowing it down.
In monogamous relationships, if one partner wants sex, or a certain type of sex, the other partner is expected to provide that. This is inherently harmful, and it will destroy a healthy relationship. Non-monogamy offers partners options for sexual expression beyond each other, and I argue that this is not merely desirable, but utterly necessary.
No specification, no elaboration that there are kinds of non-monogamy that prohibit sexual expression and that it is comparable to sexually and emotionally exclusive monogamy (and you do not go into explaining why the freedom of expression beyond each other is utterly necessary).
Additionally: About “if one partner wants […] a certain type of sex, the other partner is expected to provide that”. If I were to be monogamous and encounter the inability for getting a certain kind of sex, as an ethical person I would not by default and at all cost expect to be provided that type of sex, instead I would face the choice of reconsidering my priorities or doing away with the expectation.
Non-monogamy, on the other hand, makes no promises on behalf of anyone. It not only leaves the negotiation to the people involved, it requires that they engage in negotiation.
No specification, no narrowing it down, no discussion that non-monogamy can be done with deprivation of negotiation.
Non-monogamy reduces one’s ability to make assumptions about their partners, and this is a true asset. Furthermore, it creates more engaged partnerships, for it nurtures the autonomy of partners.
No specification, no narrowing it down, no discussion that in non-monogamy, autonomy can be (and is being) taken away from participants.
Additionally: It is not a true asset of ‘non-monogamy’ that it reduces one’s ability to make assumptions: I can assume a kind of polyamory and be a bad communicator about it and be unhappy once I realize that the other is prohibited or prohibiting things I take for granted.
Monogamy, in stripping away autonomy, strips us of our identities, it reduces us to the sum of our partnerships. Non-monogamy does not.
No specification, no narrowing it down, no mention that identity can be lost by defining oneself as a person within a non-monogamous structure, that it can be reduced to a sum of number of partnerships we have within a structure.
Additionally: What does even saying that ‘monogamy’ reduces us to the sum of our partnerships mean? People who equate worth with the number of relationships had (or not had) are the one reducing people, not a relationship model.
Non-monogamy is an extension of my ethics. It is an ethical stance, a political stance, and a feminist stance.
And no specification, except that it is an ethical stance, but without discussion that non-monogamy can be unethical.
Throughout your text, non-monogamy has been defined as, more or less, the negation of monogamy and as the relationship model that has all the necessary things monogamy does not have, and that non-monogamy is, you argue, ethical.
You do not go into explaining that non-monogamy can be unethical, or that there is an ideal, or not ideal, bad, ugly, pretty non-monogamy, that it can be the most amazing revelation ever or the most painful experience that puts people in the position to consciously re-choose monogamy.