We can only operate within the confines created by the author. Therefore, we know that the MC gets sexual pleasure from watching his wife with other men or hearing her tell the story of what happened. We know that some men may be off-limits because the MC has the ability to choose for certain events to occur or not (Ryan, Dre, Martin, etc.). We know that Anne participates because she enjoys it and for her husband's enjoyment.I'm of the mind that the problem in the relationship isn't Anne. It isn't possible to cheat in an open relationship. If it was, it wouldn't be an open relationship. What the problem happens to be is that for one reason or another Anne doesn't always want to disclose who she is seeing. Even though 9 times out of 10 her husband wouldn't mind and in fact would enjoy hearing about it (in most playthroughs). That 10th time it is because she is with someone who is inappropriate (MC's Father) or too attached (pitchfork angry cheating husband). Yet it is clear from other times she does disclose that she is emotionally involved with her partners, not just sexually, and isn't ashamed to admit how she feels in these instances.
So what is happening in the relationship with MC that she feels that she doesn't have to share sometimes? It isn't fear of repercussions and she doesn't need to worry about his feelings. He isn't going to get upset or tell other people what she has done. So the secrecy is pointless. Unless... she is feeling insecure in the relationship and is starting to feel that her husband doesn't care about her anymore. She does get upset one night about her husband being too eager to her about her having sex with someone else, professing that it makes her feel used. This is, of course, the night when the MC can choose to sleep with her mother. It is a bit of a tempest in a teacup, and it might have been as a result of an unpleasant sexual encounter that we are not privy to. Given the history of the couple to this point, it is likely that her anger was misdirected from the man she was actually upset with. It is fully possible that some of the encounters she doesn't disclose and we do not observe are not consensual.
So something about the lifestyle is hurting Anne and making her feel insecure in her relationship with her husband. Maybe even unsafe. It is opening her to mistreatment and possibly outright abuse by other men and she is probably too ashamed to admit it when one of these encounters hurts her because it will interfere with her husband's enjoyment of his fetish. Of course, it is just a theory, and it would make the game a bit of a bummer, but there doesn't seem to be many logical reasons why Anne would "cheat" on her husband in an open relationship. Perhaps this is something that is a bit of a pattern for Anne. Perhaps in her promiscuous college days not all of her encounters were consensual, and instead of dealing with her feelings or her trauma, she piled on more promiscuity to bury them. Perhaps the same this is happening again, and she feels her husband is not protecting her but rather pushing her back into those situations.
In any case, the couple has a lot to talk about. Is their relationship salvageable? In the long road, probably not. But that doesn't mean that they have to go down in flames. Maybe they need more rules and maybe they need fewer of them. Maybe it is best for both of them if neither Anne nor Tony is obligated to report who they are seeing unless they feel it is important to share. Because neither of them has been fully forthcoming in any playthrough. We know that MC has concerns and reservations that he is not bringing up to her. It wouldn't surprise me to discover that Anne shares them but will not bring them up for the same reasons. It may be that they are more on the same page than we think. Whatever is the case, all that is required is that they come to an agreement and not make demands that the other partner finds unreasonable.
It is not an open relationship. The perception of the MC's behavior relies heavily on how the user plays the game. For example, in my main playthrough, the MC is faithful and has sex only with Anne or when Anne directly approves of a woman (i.e. Emma). In this playthrough, the user must have chosen not to cheat and not to let Anne cheat (regardless, Anne will cheat). This is not an open relationship. It could be defined as sharing, hotwife, or other terms. But there ARE limits to what would be considered acceptable behavior from Anne and the MC. And the users' confusion here is important to note.
But you may have chosen to play the MC (and therefore, Anne) differently. It is possible that the MC could be a cheating liar, or sleeps with anyone just as indiscreetly as Anne. Or you could have made choices where the MC is the unrelenting instigator of marital corruption responsible for his own demise. No matter what you choose, Anne will cheat and have a number of partners the MC will not know about. The author of the game writes in such a way that we know there are some events Anne participates in that we are not privy to. Again, important to note many users question why Anne is fucking everything that walks. Why does she get so upset when told she can't participate? Why does she get so upset seeing the husband screwing a random girl? Why are there no consequences for Anne's actions (and possibly the MC depending on your choices)?
So, while your interpretation is certainly more interesting and would make for a better story, we are left with nothing more than scratching our heads and asking "what the fuck?" As of the current update, there are no answers. There is nothing in the story to suggest that these courses of conflict will be used. The sex does get monotonous for many viewers (there are others who are content with no logical story whatsoever).
My version of the MC is left wandering the resort constantly searching for Anne, never getting laid, and wondering what the fuck is going on!? And I am not happy with that story outcome. I could change it and make him wander around, getting laid, and still wondering where the fuck is Anne. The only conclusion I can draw at this point is that the author is not capable or does not desire to write a compelling story that uses all of these points of contention to his advantage. BUT, this is a work in progress. It is completely possible that the next 10 chapters are devoted to ironing out these discrepancies. Like many viewers that are hanging out here wondering what is next, I remain hopeful that the story will resolve itself, however unlikely that may be.