Q. Recently, a male friend and I dined with another couple at a very fine restaurant. The other gentleman was sharply reprimanded by my friend for making improper advances toward me. For the duration of the meal, the other fellow practically had his chin in his potatoes. Needless to say, it severely dampened the evening.

To show that there were no hard feelings, I invited my friend and the other couple to my home for a night-cap. This same gentleman promptly fell asleep on the floor. The rest of us proceeded to enjoy each other's company.

Was I wrong to feel an obligation to extend an invitation to come to my home? When the gentleman slumbered on the floor, should I have made an effort to wake him and include him in the festivities? Or should I have offered him the guest room since he was apparently so tired? In light of what had transpired earlier, I was perplexed. What course of action would you have taken?

A. The course you are taking, which is to meet each successive rudeness with a compensatory politeness, strikes Miss Manners as the route to disaster. What will you do if the gentleman behaves improperly after you have moved him into the guest room? Turn over the whole house to him?

Miss Manners believes in meeting rudeness with kindness, but this is ridiculous. Her course of action would be to awaken the man gently -- unless he got on the floor in a heap all at once, as opposed to stretching out on it as if it were a bed, in which case a vigorous awakening might be more effective -- and to suggest to him politely that he might be more comfortable at home. His home.

Q. I recently moved to Washington from Phoenix. Where and when may I wear shorts in public? I especially want to know if I may wear them to the supermarket. I am a woman , 30 years old, 5-feet-6 tall, and I weigh 100 pounds.

A. Washington supermarkets are generally informal, which is to say that one dresses less for them than for afternoon embassy receptions, but more than for sun-bathing on apartment house roofs. You may wear shorts, but may not expose the mid-riff; you need not wear gloves, but you should wear shoes. Washingtonians are too polite to stare if you should dress inappropriately for the supermarket, but you run the risk of not being invited back.

Q. I was always taught that dinner was the large meal in the evening, and the last light snack was called supper. But, I hear so many people refer to their large meal as supper that I am wondering if I am correct.

What about lunch and luncheon? If I suggest to a friend that we meet at a restaurant at noon, I say, "Let's have lunch today," but if the meal goes well beyond the ordinary fare and is served to four or more persons, I am confortable enough if someone calls it a luncheon.

The economists say, "There's no such thing as a free lunch." Should they say luncheon?

A. Dinner is the main, hearty meal of the day, and if you insist on eating it at midday -- which is only exusable twice a year, on Thanksgiving and Christmas -- you can't have another dinner at night, or you will make yourself sick. The lighter, evening meal is therefore called supper, as is the very late meal -- at a dance, or after the opera -- because a sensible person would have taken the precaution of eating dinner first.

Lunch used to be luncheon's nick-name, but the longer word is chiefly used now to indicate big deal occasions, such as you describe, and in writing, rather than in speech.

The economists are not wrong for once, however. There is such a thing as a free luncheon, if you know the right people.