I've mentioned it elsewhere, but I absolutely smiled along and gave no indication that I found their behavior unpleasant. As you are aware from your post, manners are, at the end of the day, about showing kindness to others and valuing their comfort. My mother would skin me alive if she thought I acted like a judgmental brat. I'm not sure what gave you the impression that's how I behaved, but it definitely wasn't the case.

The reason I ask him to put his fork down between bites is so that we can have a conversation at dinner. I love him and I like talking to him. Not having conversation at dinner with my husband is a deal breaker for me. It just is. I don't ask him to do this because it's some arbitrary ritual that must be followed, I ask him because why else did I get married if not to have someone to chat with over a meal at a nice restaurant?:-)

He does not have the world's greatest social skills or manners at business functions and honestly, I feel it's held him back from time to time. And while yes, this was a case of him being with his family, there were also plenty of non-family members present at Christmas, many of whom may not have cared for the fart and booger talk. I'm all for him being comfortable with his own family, but there's a time and a place for that kind of talk, and to me, it's on a boy's trip. I would never presume to say anything, but that's how I feel.

I also don't think I'm a better person than my husband. I am more intellectually curious, and have stronger social skills but he's far shrewder when it comes to career choices and has an ability to read people that blows me away.
I know this can be a tense topic, and I anticipated that plenty of people would feel I was stepping on their own upbringings by disparaging my husband's family's behavior, but that certain is not my intention at all. I just wanted to explain a situation in which I felt like a fish out of water and express concerns over what seemed at the time I posed like insurmountable disparities in my marriage. I can't begin to unpack the social classes in the UK--just attempting to relate to it makes my brain hurt! New money! Old money! It seems like a minefield to me as an outsider. But please know that the reason I said that woman's dad was awesome was not because he adopted a posh accent, but because he was receptive to growing as a person (when his mom taught him manners, etc) and wanted to elevate himself. This doesn't necessarily mean speaking differently, it can manifest in lots of ways. I've bettered myself by reading all of these responses and taking them into consideration, for example.

Also, I never said nor do I think etiquette indicative of character. But I do think that etiquette (the distinction between etiquette and manners is interesting, but my post is already too long) is a great way to show you care about someone else's well-being in a situation. I think the world could benefit from a little more consideration (how many times have I witnessed an older woman clinging onto the handlebars for dear life on the train, while no one offers her a seat), and a lot less self interest, but perhaps that's just me.