oh goodness yes. there was the very traditional proposal (but with a non-diamond!) that i wasn't expecting and we hadn't discussed (though he was right to know I'd say yes) and the mostly-traditional wedding (i was walked down the aisle and traded between men--though i'm so terrible at being looked at i probably wouldn't have gone at all by myself). we thought a lot about it and ended up with an event we loved, full of our favorite people and snacks and minimal princessing (my outfit was an inexplicably white bridesmaid's dress). i did NOT change my name, for which i am grateful every day, but i did end up giving our son his name only, for which i am disappointed with myself and still, six months later, consider changing. ugh, the patriarchy is hard.
I work with elementary-aged kids (5-10 or so) and grew up with a brother fifteen years my junior, so I'm pretty familiar with this age-rage both in and out of their own homes. And this is nonsense. It seems like the parents wanted a vacation/break from parenting and forgot that your kids actually have to be somewhere else if you don't want to parent them. Bringing them to someone else's home does not = dropping them off at camp. It definitely sounds like they weren't given enough to do AND that their parents failed to step in when discipline was called for. Your nice teacher husband was right! They ARE losing valuable instruction in empathy and carefulness, which is a bummer.
However, I think he's also your best tool here: I imagine he knows how to make corrections without displaying anger or issuing a punishment, yes? The idea that you're somehow judging them or their child is most likely to create defensiveness in the parents. But (should you choose to host badly behaved children in the future), he could step in cheerfully and say, "Oh no, look! You've got some dirt on your shoes and it's making these footprints. Can I help you clean them up?" Then the two of them CLEAN UP TOGETHER in a friendly fashion. This tells everyone that you have boundaries and expectations, but that you're not angry or judgey about it. PLUS, it shows a good faith effort in case you have to go to the parents later about a bigger problem.
@iceberg YES. Upon announcing my pregnancy, I was asked by multiple unrelated people whether we had been "trying." Which (besides making everyone in the room picture our sexytimes) basically means, "so was this an accident?" It would be a win for society if we could collectively figure out which "innocent" questions are actually ENTIRELY about your junk.