Disparaging tourists is such a popular summer pastime that even tourists who are in the very act of touring like to have a go at it. "This place is overrun with tourists," they will say in disgusted tones. And there are more of them than they think, because they fail to count themselves.

If this amuses them Miss Manners is not one to interfere, provided they do not insult their fellow tourists to their faces. But she has noticed that this disparagement of their own kind suggests a way of thinking that is likely to lead to post-holiday etiquette problems for all who travel.

When the residents of a tourist attraction criticize tourists, it is for such crimes as crowding and littering the area, dressing as if cities were beaches and supporting the local economy. (No, wait. That last one isn't quite it. It is for supporting the local economy by buying souvenirs and snacks instead of patronizing sensible businesses that sell things real people need, such as lawnmowers, dishcloths and stepladders.)

But when tourists criticize one another, it is for not enjoying themselves. This does not mean getting in the way of their critics' enjoying themselves, although there is an element of that. The charge is, uncharitably enough, that other tourists are not enjoying their own vacations.

"Look at them," they will say of one another. "They have no real interest in being here. They don't even know what they're seeing. They don't care. All they want is to be able to brag to their friends at home that they've been here. That's why they're taking pictures all the time and sending all those postcards. It's just to prove that they've been here."

Backpackers and those in hotel suites say this of one another. People visiting a place for the second time say it of people visiting for the first time. And everyone says it of people traveling on tours -- especially the other people who are on their tours.

What worries Miss Manners is that they thus plant in themselves the extraordinary notion that telling people at home about one's trip is a real and desirable possibility -- that it is so much of one that huge numbers of people invest the better part of their disposable time and money in setting up what Miss Manners can tell them will be a social disaster.

Nobody wants to hear about anyone else's trip. The only thing they dread more is looking at the pictures from such trips. Here is the conversation family and friends want to have with the returning tourist:

"Have a good trip?"

"Yes, it was great."

"Good weather?"

"Well, it rained one day, but we were going to museums then anyway."

"Okay, then. Good to have you back."

Of course, the tourist who did have a great trip is bursting with things to say and show. For that, it is no use to corner those alleged folks back home who are supposed to be impressed. The only people who genuinely want to listen are those who have been there themselves or are planning to go, and the trade-off is that they expect equal time to tell of their adventures and impressions.

Tourists should therefore treasure other tourists. They are the only ones who will want to listen to them.

Dear Miss Manners:

I love red wine, but it always leaves an unsightly stain on my lips and teeth. This makes me hesitant to drink it in public, because whenever I smile I'd reveal a mouthful of purple teeth. Is there a way to drink red wine without turning one's mouth purple?

Quick! Somebody run and get the soda water! You could, ah, gargle with it. Well, no. Good thing this isn't the household-hints department.

Not that etiquette will be much help after the fact. Miss Manners can only tell you what it says you can't do. You can't ask for a straw. You can't whip out a mirror and inspect yourself. You shouldn't even try using a knife blade as a mirror (as one Gentle Reader once suggested) because it is not polite to brandish knives around during dinner.

So she suggests that you learn to drink by putting the lower rim of the glass beyond your lower lip and raising your upper lip and teeth out of the way. However, if you cannot manage this without looking as if you are gargling, Miss Manners recommends drinking milk.

Feeling incorrect? E-mail your etiquette questions to Miss Manners (who is distraught that she cannot reply personally) at MissManners@unitedmedia.com or mail to United Media, 200 Madison Ave., New York, N.Y. 10016.

(c) 2004, Judith Martin