YOU WERE BROUGHT up to believe that you must at least toy with food that you cannot stomach, as it were. As a guest in someone's house, you are served a dish you cannot eat. Perhaps you are allergic to it, perhaps it is against your religion or principles, or perhaps you just hate it.

What you do, to be polite, is to mess it up. Grabbing the top of your fork, to keep as much distance as possible between you and the despised goody, you shove it from one end of the plate to another. Or you hide it under the nearest green leaf. If you are really adventurous, you might excuse yourself and drop it into the potted plant, the dog's mouth or the toilet. Anything to avoid admitting, that you haven't yummed it right down.

If everyone followed these rules, Miss Manner would not be eating lobster salad today. And Miss Manners is excessively fond of lobster salad.

The young gentleman who was originally served this very lobster was not. The young gentleman, as Miss Manner's houseguest, was expected to jump out of his dining room chair with the thrill of it all when lobster was passed. Lobster is not served all that often in private households these days, what with the difficulties of taking out second mortgages.

Indeed, he did try to look pleased. But there was a distinct difference between his valiant version of the look and the genuine versions that appeared elsewhere around the table. And when Miss Manners called him on it, he admitted his true reaction to seeing what he considered a hostile-looking crustacean staring up at him.

Miss Manners would not have solicited this response under many circumstances, and the young gentleman was correct not to volunteer it until asked. If it had been a large dinner party, for example, Miss Manners would not have undertaken to deal with the problem, preferring to consider it that the hostess' responsibility ended with providing edible food and that any difficulties after that were the responsibility of the guest.

However, this was an informal gathering, and Miss Manners was pleased that the young gentleman had the sense to respond frankly to her question. There is a limit - directly relating to the price per pound - to foods that should be messed up for the sake of manners.

So the young gentleman got scrambled eggs, and Miss Manners gets lobster salad. And Miss Manners does not have to worry about which of her plants or plumbing fixtures was sacrificed to a guest's desire to look polite.

Miss Manners Responds

Q: Please advise as to the proper way to sign a card, such as a wedding card. My boy friend and I were invited to a wedding and I signed the card "Julie and Ed." He insisted that the proper form was "Ed and Julie." Also, would you sign the card the same way, using first names, if you were married?

A: Regardless of gender or marital status, the person who writes the joint signature on such a card puts his or her own name last. Signing only first names in a situation, such as a wedding, when the recipients will be hearing from large numbers of people, is always fun because it gives the bridal couple an opportunity to sit around saying, "Gee, I don't know, they must be friends of yours."

Q: What is the etiquette for staff members of agencies such as the Department of Human Resources, St. Elizabeth's, Lorton, etc., when interviewed by news media staff in the course of an expose?

A: The conventional procedure is to tell everything one knows at the time of the interview, and then to say afterwards that one was quoted out of context.

Q: The man who sits at the desk across from me at work eats the cores of apples after he has finished the apples. It drives me crazy. But he says if's more polite than throwing the core into the wastebasket. What do you think of his solution?

A: Fine, as far as it goes. What does he do with the crab claws served at cocktail parties?