I think most brides go to find a gown that they will look good in, not one in which they are trying to look bawdy enough to keep the groom's sexual attentions on them.
I agree with the LW that maybe these folks would have been better off looking in a lingerie store instead of a bridal store.
It is certainly not good etiquette for the bride to dress as if she is trying to attract the sexual attentions of anyone--it is assumed that the bride already has the sexual attention of the groom.
These people were crass and should not have drawn the sales clerk into their sleazy little drama.
For the record I think that the bride and her family sounded very demanding, but the LW was the rude one IMO. There's a line between a suggestion and imposing your views on others, and when the LW repeatedly refused to take the bride's request into account, she was imposing her own tastes onto someone else.
I think though that the LW thought she was helping a regular bride and it turned out not to be the case. The bride was not looking for a dress like most brides are, she was looking for something sleazy. Would you expect the salesperson to come up with a dress that looked sleazy on her?
I don't think that's reasonable. And the dress shop apparently didn't have what she was looking for because the bride herself perused the aisles and couldn't find something cut low enough for what she wanted--she was not limited to what the LW was bringing to her.
Essentially, they told the salesperson that there wasn't anything sleazy enough for them in her shop. I wouldn't want to deal with people like that either.
Taste doesn't even enter into--its more of a lack of taste. How distasteful can it be to dress in a bawdy way for your wedding because you can't keep the groom's attention. Sounds like a bad situation all the way around. And since wedding dress shops have to have repeated contact with their clients I can well imagine that the LW was relieved that they didn't find what they were looking for.