IT WAS A WOMAN who first told me about Alan Harris. We were walking downtown when she told me about him and when we came to the corner where his shop is located, she pointed to the place and said I should go in some day and see for myself. So the next day I returned and sure enough Harris was there. He is 22 years old and friendly and conceded that there are some women who stroll into his shop, take a look at him standing among the lingerie and simply go to pieces.

That's pretty much what happened to the woman who told me about Harris. She is a colleague, a liberated woman of the first rank - very independent, totally in control, takes lip from no one, curses with the best of them and was last non-plussed some time in high school. She went into the shop to buy a strapless bra and when Harris went up to her and asked. "May I help you?," she was startled. It was a man. She thought fast and lied. "Yes, I was looking for a slip." Alan Harris gave her the professional once-over. "You're the type who wears 'nude' underwear," he said. The woman, the toughest woman I know, went to pieces.

Harris showed no mercy. He talked underwear. He talked size and style and used all the special nomenclature. The woman who told me the story could not take it. She felt herself losing control. She could not deal with Harris. She bought a slip she did not need, did not buy the bra she needed, and exited onto Connecticut Avenue, shaken.

I talked to another woman who had been to the lingerie shop. I interviewed her at her desk and she looked around while she was talking to me as if she were passing me A-bomb secrets. She told me how she feels. She told me she feels that it is totally all right for Alan Harris to sell women's underwear. That is her position. That is her intellectual position. Then she looked around once more and said she had something to add. She didn't like buying her underwear from a man.

For the record, it is important to say that Harris works at the store because his father owns it. The two of them decided some time back that for safety reasons it was prudent to have a man always on the premises. They also always have a saleswoman on duty, and while I was in the store, for instance, at least one customer breezed right by Harris and dealt with the salewoman in the back.

No matter. I am not really writing about Harris, but about something else. I don't know what you'd call it, except that it has something to do with sexual confusion - with instances when ideology comes up against instinct or habit or whatever you might want to call it. It is, for instance, one thing to subscribe to the belief that people are simply people and something else when the person selling you your underwear is a young and, I suppose, attractive man.

From what I hear I think women have always had this problem with male doctors and I think men have had this problem with nurses. These are other examples. Some men, for instance, find stewardesses sexually confusing, and they are forever hello to you, pours you a couple of drinks, leans on your armrest to chat with you and asks you where you're from, that she's interested. For such men, life is tough. For such men, life ought to be tough.

Anyway, what's happening now is that women, and to a lesser men, have been breaking out of their traditional roles and asking to be judged as people, not as either men or women. This is as much true of the so-called househusband as it is for the female coal miner.

The fact of the matter is, though, that whenever admit to some confusion, to some momentary lapse, when I look at a person and I see a woman instead, when I refer to that first time maybe a couple of years ago when a woman fitted my trousers and I was so nonchalant my stomach knotted - when I sometimes use a word in a column I shouldn't, I get told off for it. I should know better. I'm always seeing women where I should be seeing persons. I hang my head. I am, I know, flawed.

But good old Alan Harris has turned the tables. For once, the sole is on the other foot. I said something like that to the woman who had told me about Harris and she did not seem to understand. She suggested I go to the store myself. I did just that, and talked to Harris. I don't know why the woman made such a fuss.

He's just your average, red-blooded American person.