It's not a man's world in Georgetown, especially if the man is looking for an even break at an M Street "meet market."

Fred Larkin is the latest to discover that, when it comes to D.C. nightlife, the fair sex is also the favored sex.

Fred decided to drop by a place called The Library on the evening of April 9. Before dropping, he donned a pair of jeans he had bought on a recent trip to Scandinavia.

"These were $30 jeans," Fred said. "It was the second or third time I'd worn them. No holes, no patches, no grease stains. They were almost new. They looked great."

But imagine Fred's amazement when the maitre d' refused to let him in. "No jeans permitted," the maitre d' said.

Then imagine Fred's amazement when a young woman waiting in line directly behind him was admitted with a smile. She, too, was wearing jeans -- a pair that Fred describes as having been through the washing machine more times than Carter has liver pills.

Ed Lewis, assistant manager at The Library, insisted that the establishment has "a very strict dress code. There is absolutely no way anybody could get in here with a pair of jeans that you would wash your car in."

Then Ed added this: "Both men and women can wear nice jeans, though. Just nothing faded."

In other words, Fred, it's all in the eye of the beholder. What I think you ran into was a question of demographics rather than denims.

No "meet market" can live up to its name or pay its bills unless its clientele is close to 50-50, men-to-women. Most meeteries attract about four males for every female. Even though the management denies it, I suspect that Fred happened to pick a night when The Library was short on ladies, not a night when the maitre d' suddenly decided to hate a $30 pair of pants.

Oh, ye of cluttered attic, ye of congested basement, all ye who would wish to correct past sins of clumsy collection, deliverance is at hand.

As it does annually, the Association of American Foreign Service Women is seeking donations for its Bookfair '86. AAFSW is after books, art, stamps, records and foreign coins. All gifts are tax-deductible, and AAFSW will pick up contributions, if donors call Barbara Huso at 223-5796 any weekday except Wednesday.

Parents quickly learn not to expect appreciative applause from their fellow adults. Much more likely are apprehensive stares that say, "Please don't let your terrible, rotten kid drop ice cream on my shoe," or "How could you allow that child to grow up to be so-o-o-o-o awful?"

But Penny Flecker of Columbia ran into a vastly different reception the other day. Hers is a tale worth telling, so that a certain anonymous man can collect her heartfelt thanks, and so that every parent will know that such things really do happen.

The date was April 19. The place was the Sir Walter Raleigh restaurant in Ellicott City. The occasion was the 12th birthday of twin brothers Norman and Alexander Flecker. Penny and her husband, Manny, were on hand, of course, as was a friend of the boys, Jeff Wadle.

Eating done, the Fleckers asked for the check. But the waitress said it had already been taken care of, by a man who had been sitting in the corner.

Why had the man laid out $50 or so for the meals of five perfect strangers? According to Penny, "He told the waitress that it was nice to see kids so well-behaved."

Penny says the Flecker party was "flabbergasted." As for their benefactor, I'm not sure words exist that would do him justice.

James E. Lehman Jr. of Ashton, Md., describes himself as "a person who loathes waste." But he's about to rewrite his personality profile. He is being driven mad by "plastic peanuts."

You know these infernal things. They're made of styrofoam, and they're used to surround breakable items before shipping. Every package you open contains hundreds of them. You and I throw them in the trash without a second thought. But James never has. And now those plastic pests are starting to crowd him.

"Please, Mr. L," he implores. "What do you do with several 50-gallon bags of these things?

"Is there a center where one may recycle them? Have they a resale value? If sent to a landfill, do they decompose?"

The only one of those questions I can answer, my poor peanut-infested correspondent, is the last. Styrofoam will decompose, although it takes its time. As for the other questions, does anyone out there in Readerland have answers?

Bob Orben's definition of a true conservative:

One who gift-wraps his Form 1040.