This is an excellent breakdown of what I tried to articulate regarding "filling in assumptions in a hypothetical"
I've only been married two months, so I can't stake any longevity experience. As I wrote here in response to a further comment, it's really difficult to imagine how exactly I would react when a hypothetical scenario requires me to fill in so many assumption gaps. For one, I would find it alarming if my non-drinking wife got that intoxicated. I was previously in a relationship with someone who had a history of severe manic episodes, and it was deeply unsettling to always have to scrutinize her behavior through the lens of "does she really want this or is this a sign of burgeoning mania?"
I think this is correct. A parallel scenario could be agreeing to go vegetarian but then asking for an upper limit for how much meat you can eat second-hand from your friends (since they were going to throw it away anyways). You would be revealing a frequency graph that is similarly increasing up to the policy line, indicating serious reluctance to be a vegetarian. There's nothing wrong with this necessarily, but if someone is screening you for how much you really care about being vegetarian, it's reasonable for them to harbor suspicion.
I have a desire to be super rich, but it's either unlikely to happen or not worth pursuing. I have a desire to be an elite athlete, but it's either unlikely to happen or not worth pursuing. I have a desire to fuck an endless parade of super models, but it's either unlikely to happen or not worth pursuing. It's very possible that I would feel differently about pursuing multiple relationships if the chase was either much more effortless or more rewarding. Yet the number of sexual partners I've had already easily puts me in the top <1% of males on that metric. So if I'm expressing reluctance despite that relative advantage, I'm very skeptical how much my preferences would change much in response to greater opportunity.
Extreme hypotheticals can be useful in exploring the outer fringes of our positions, but they do a very poor job of informing our day to day conduct. I'm not averse to engaging with your "drunk wife meets sexiest person in the world" scenario, but for me to give any semblance of an answer requires me to fill in a multitude of assumptions that are too numerous to fully catalog (ex. how did my non-drinking wife get drunk? is she a materially different person when severely intoxicated? whether I went with her to the house party or not, how did my introverted wife find herself alone with the world's sexiest stranger? did I abandon her? etc etc.). Unless I'm specifying each and every assumption I'm relying upon, it's virtually guaranteed that you'll hold a different assumption, which would necessarily change how you interpret my answer. I don't understand what you find enlightening about this hypothetical.
It seems far more relevant to me to think about far more common scenarios, but I don't know if probability is the best way to contemplate this though. I can certainly imagine scenarios where my wife is smitten by a friend/co-worker/barista/whoever and if that happens then we can end our relationship because I wouldn't want to get in her way. I don't think about this scenario prospectively because there's no reason for me to care about it if it hasn't happened. Whether the risk of this scenario happening is 1% or 99% in the future bears little relevance to what I do in the present; I'll continue my relationship so long as it is satisfying.
Pascal's Wager is a good comparison here.
I said "my partner could be smitten by a particularly motivated sexiest person in the world" but you translated that as "she has a high probability of yielding to temptation in that scenario". I also did not say anything about what the scenario would reveal about her character (I'm not even sure what that means) but rather what it would reveal about her preferences. If you have a point I believe you can make it without mischaracterizing my statements.
I meant "date" expansively, so yes "date or have sex with". I don't want to be with someone who has an active desire to have sex with other people. Your guessed answer is off. I don't deny that either myself or my partner could be smitten by a particularly motivated sexiest person in the world, but then again I don't know how relevant such an extreme hypothetical could be. But if it did indeed happen, I would have no interest whatsoever in placing any restrictions on my partner after the fact. They expressed their revealed preferences, so it's best to let them go so they can pursue it. Even if they don't have a subsequent shot, I would have no interest in staying with them.
There is no one monogamy rule, but a range of expectations. For me it's that I don't want to date someone who has an active desire to date other people. From that standpoint, this is neither a rule nor is it a restriction. I wrote this above, and I don't understand why it's seemingly so difficult for others to parse.
The answer to your interrogatories for me would all boil down to "are my partner's actions indicative of a desire to date other people?" From that standpoint, there's no reason for me to care about handshakes, or kisses on the cheek, or a wayward glance, or even flirting, because that's not really indicative of this desire. Even random make-outs with a stranger at party might not be indicative, depending on the context. I wouldn't want to be lied to about this desire, so I wouldn't want to be flattered under false pretenses.
In terms of how long that exclusivity desire can last, I don't know! I can't claim to predict the future. Maybe it will end tomorrow or never (both very doubtful). I never made a claim otherwise, and I agree that would've been an example of self-delusion. I will remain in my relationship so long as it is worthwhile, and from my current standpoint I don't see any obvious reasons for that to diminish anytime soon, but you never know. I am comfortable with that risk.
Regarding the why I want restrictions, I don't. I am not restricting my wife from doing anything she wants to do, and neither is she to me. If she gains a desire for others, I wouldn't want to stand in her way. Doing so is absolutely anathema to my principles of prioritizing individual freedom and autonomy.
I don't understand, how is it missing the point? "Interest in more than one" is necessarily affected by practical concerns, non?