A GENTLEMAN of Miss Manners' acquaintance was having a cozy chat with her about the demise of his marriage. "Funny--I was such a good husband," he mused. "I have total recall, you know, and so I was able, every time she did something wrong, to recite to her everything she had done wrong from the day we met."

An elderly lady of Miss Manners' acquaintance was bemoaning a recent tiff with her sister. "She's right, you know--I was a brat. No question. If Mamma didn't let me do something, I'd cry, and since I was supposed to be delicate, she'd give in and let me do it. I used to get her to make the older children take me with them and their friends, or to give me things they didn't want to. But it was 60 years ago. I haven't done it since."

Miss Manners began to see the need for a device capable of wiping out blots on personal records. The alternative seems to be to wipe out the relationships that existed when the errors were made, and that does not seem to her to be satisfactory. All this running about, seeking fresh people so that one can start a fresh record is getting very tiresome, indeed.

There are two such mechanisms in existence, the Apology and the Explanation, but they do not appear to be doing the job. The apology is an attempt to state that there was no direct motivation for the offensive action, and the Explanation is a statement of what the motivation was.

It is not hard to imagine, therefore, why the apology is more effective. "I'm sorry . . . I didn't mean to . . . I never dreamed you'd mind . . . It was an accident," and so on, are useful in atoning for many transgressions. But this quickly wears out. Along about the third time the same person steps on your foot, the apology doesn't quite work any more.

The Explanation has had a great vogue for the last decade or so, but Miss Manners never understood why. "I know it was a bitchy thing to do, but I was mad," once offered in explanation for a slander, did not inspire her to reply, "Oh, that's quite all right, I understand." Nor was she touched when offered, upon the discovery of a lie, the explanation of "But I was afraid if I told you the truth you'd be angry."

That people do bad things because they have reasons for doing so seems, to Miss Manners, self-evident but not charming. It is only when the motivation is better than its result ("I was only trying to help . . .") that it counts, and in that case it should be classified as an apology.

What is needed here is a more effective tool for expunging mistakes that are not being repeated--a sort of social statute of limitations. If society allows criminals to pay their debts, relatives should be no less generous.

What term shall we set? It does seem, in the case of the whiny child, that 60 tantrum-free years should be considered sufficient evidence of rehabilitation. But the case of the failed marriage suggests that perhaps a shorter term should be set, as the lady did not seem inclined to stick around long enough to work off that long a sentence.

Whatever the time we agree upon, provision should also be made for earlier trade-offs. "If you forget about the time I . . . I won't mention that you . . ."

Special attention must be given to the question of re-classifying fault-citing as teasing, and thus removing it from time restrictions. In the case of repeated mentionings, both teaser and teasee must agree that the reference is at least faintly funny.

That plaintive statement, "I suppose I'm going to hear about this for the rest of my life," deserves a kinder rejoinder than, "That's right." MISS MANNERS RESPONDS

Q. I'm a law school student with a strange problem. Four weeks ago, I met a man who goes to another college nearby. When we went back to his apartment, I discovered that his place was full of lizards. Most of them were in cages or jars, and a few ran around in small boxes. I was nervous, because I've never liked lizards. Anyway, I relaxed and enjoyed the evening. It wasn't until later on, when he was taking me home, that he told me that lizards often escape and hide in various places.

Just last week, the two of us and another couple went out for dinner to a fancy restaurant. Halfway through the meal, Mark reached into his pocket, held his hand across the table, and then opened it. A big lizard jumped into the air and then ran up his sleeve!

I was shocked! I felt really dizzy and then just blacked out. When I came to, I discovered that I'd fainted and fallen face-first into Mark's friend's lobster newburg dinner. There were big hunks of lobster in my hair, and my face was covered with sauce. Half the restaurant was standing around, trying to help me. As you can guess, everyone at the table was embarrassed.

Since then Mark hasn't called me. Neither of the other two people will talk to me. I don't know what to say to them. I'm still so embarrassed. I want Mark to call me, but I'm too embarrassed to call him. What should I do?

A. Shampoo your hair immediately.

Q. I recently entertained two clients at one of the better restaurants. While ordering our meal, I became confused about who should order first. Ladies first? Clients first? Female clients, myself, and then the male client? Unfortunately, the waiter did not assist us in this awkward situation. By the time the check came, he was totally confused, because each course was handled in a different order and he had no idea who to give the check to.

Outwardly stating that I was entertaining clients would be improper. As more women are entertaining daily, please help us make this situation as comfortable as possible, so we can get down to business. It's already difficult enough trying to get a good table, instead of next to the kitchen!

A. It is difficult enough for a waiter to get through swinging doors carrying loaded trays without his being expected to distribute the roles.

You must therefore make it clear that you are the hostess, which does not involve distinguishing the business nature of the meal from one held for social purposes. Speak up, asking your guests in turn what they would like to order. Address women first, in descending order of age, and then men. You then repeat their answers to the waiter, although naturally he has already written down what he overheard. Give your own order last. If the waiter does not conclude from that that you should get the check, then, when the time comes ask for it. You will be surprised at how little this tends to embarrass others.