Not only was I not taught (or even informed of) these formal dance rules posters keep mentioning, I know no one who was. Ask every woman at a table to dance? Ask any woman to dance? That happens? In real life? Like a man walks up to a woman and puts his hand out and formally asks a woman to dance? For real? Yesterday I would have bet a $100 that modern day men don't seriously do that (they might do it being goofy, but not as a normal thing) and I would have thought I was making easy money. And I have been between being a guest and a waitress to well over 100 formal weddings. Never seen it. Never, not once.
So I think its plenty normal for the LW woman to have only the frame of reference of couples slow dancing together where 99% of the time they get up to dance wordlessly or the woman asks her partner to please dance with her, or maybe once in a while a man hitting on a woman slow dancing. And if it is strangers, again often its the women who dominate on a dance floor at a wedding, not men. Not some sort of situation where a man is going to go around the table of 8-12 he's sitting at and formally asking each female for a turn of the dance floor.
And yet it has happened to me - in the example in my opening post, in fact.
My friend and I were sitting at a table at the edge of the dance floor, and these two gentlemen walked up to us and put their hands out and said "Would you ladies care to dance?" Several of their friends asked other single ladies to dance (there were about 6 of them iirc). The gentleman put his hand on my waist and put my hand on his shoulder, took my other hand in his hand and led me in a lovely dance. It was wonderful. Really, truly fun
I wished then and I wish now that more young men were like that. He was several years younger than me (I was just 30 and I think he was in his early 20s - possibly younger).
It does happen.
Then again, the bride and several of my friends were fans of Jane Austen. Many of my friends are also members of thelocal Jane Austen Society. It is entirely possible that these young men actually *were* intructed in formal etiquette.
However, I also know that many of my other guy friends are NOT and have not been instructed in formal etiquette and, single or not, will often go out of their way to ensure that their wives' single girlfriends get turned around the dance floor at least once in a slow dance song.
It's a shame that the way dancing has changed has also changed society's attitude about it.