This is not really hypocrisy, it's actually the way belief often works. An example of this is an Israeli politican who is an atheist. She was asked if there was any problem with her being an atheist, and she said "I don't believe in God, but I believe in the Jewish people, and the Jewish people believe in God." Or maybe that you don't think there's anything wrong with infidelity, but you are outraged that someone made it public because it will corrupt the morals of the youth or something. It's even possible for no-one to literally believe that infidelity is wrong, and yet the belief still works because everyone assumes that someone else believes and wants to preserve their belief. This explains the phenomenon of a pastor of a church who is an atheist, but nonetheless every Sunday promises the congregation they will be together in the afterlife. In order for belief to be operative in a culture, it's not necessary that people actually believe, only that they assume someone else does.
It is, as you say, the way belief often works; this doesn't make it not hypocrisy, it just means humans are often hypocrites. (Though, I get the idea that the use of that term on LW and OB may differ a bit from the usual usage; here there does not seem to be any implication of conscious or deliberate hypocrisy. This may in fact just be a definitional dispute.)
I'm not claiming that the actual rule is "Don't get caught." If that were the case, the authorities would simply say that. This kind of rule is like the rule against public nudity: you are allowed to be nude, just do it discreetly, in private. You are only prohibited from letting yourself be seen nude by others, from being caught. Or other examples, like urinating, defecating, etc. No-one thinks that people aren't ever naked, or that they don't defecate, we know it's just done privately. People use euphemisms and say they are going to the "restroom" (to rest?), but we know what they are doing, they just don't say it directly.
This doesn't seem to be analogous. People are explicit about the fact that the rules are "don't go naked in public", etc., and not "don't go naked". This is not the case with non-monogamy.
Many of us are familiar with Donald Rumsfeld's famous (and surprisingly useful) taxonomy of knowledge:
But this taxonomy (as originally described) omits an important fourth category: unknown knowns, the things we don't know that we know. This category encompasses the knowledge of many of our own personal beliefs, what I call unquestioned defaults. For example, most modern Americans possess the unquestioned default belief that they have some moral responsibility for their own freely-chosen actions. In the twelfth century, most Europeans possessed the unquestioned default belief that the Christian god existed. And so on. These unknown knowns are largely the products of a particular culture; they require homogeneity of belief to remain unknown.
By definition, we are each completely ignorant of our own unknown knowns. So even when our culture gives us a fairly accurate map of the territory, we'll never notice the Mercator projection's effect. Unless it's pointed out to us or we find contradictory evidence, that is. A single observation can be all it takes, if you're paying attention and asking questions. The answers might not change your mind, but you'll still come out of the process with more knowledge than you went in with.
When I was eighteen I went on a date with a girl I'll call Emma, who conscientiously informed me that she already had two boyfriends: she was, she said, polyamorous. I had previously had some vague awareness that there had been a free love movement in the sixties that encouraged "alternative lifestyles", but that awareness was not a sufficient motivation for me to challenge my default belief that romantic relationships could only be conducted one at a time. Acknowledging default settings is not easy.
The chance to date a pretty girl, though, can be sufficient motivation for a great many things (as is also the case with pretty boys). It was certainly a good enough reason to ask myself, "Self, what's so great about this monogamy thing?"
I couldn't come up with any particularly compelling answers, so I called Emma up and we planned a second date.
Since that fateful day, I've been involved in both polyamorous and monogamous relationships, and I've become quite confident that I am happier, more fulfilled, and a better romantic partner when I am polyamorous. This holds even when I'm dating only one person; polyamorous relationships have a kind of freedom to them that is impossible to obtain any other way, as well as a set of similarly unique responsibilities.
In this discussion I am targeting monogamy because its discovery has had an effect on my life that is orders of magnitude greater than that of any other previously-unknown known. Others I've spoken with have had similar experiences. If you haven't had it before, you now have the same opportunity that I lucked into several years ago, if you choose to exploit it.
This, then, is your exercise: spend five minutes thinking about why your choice of monogamy is preferable to all of the other inhabitants of relationship-style-space, for you. Other options that have been explored and documented include:
These types of polyamory cover many of the available options, but there are others; some are as yet unknown. Some relationship styles are better than others, subject to your ethics, history, and personality. I suspect that monogamy is genuinely the best option for many people, perhaps even most. But it's impossible for you to know that until you know that you have a choice.
If you have a particularly compelling argument for or against a particular relationship style, please share it. But if romantic jealousy is your deciding factor in favor of monogamy, you may want to hold off on forming a belief that will be hard to change; my next post will be about techniques for managing and reducing romantic jealousy.