ABOUT THREE WEEKS AGO, I discovered the television show "Dallas." In fact, I had sort of been watching it for months, keeping one eye on the tube and the other on a book or magazine, letting my wife keep track of things. Now, however, I am hooked. I think it happened when Sue Ellen stopped crying long enough to have another affair.

That Sue Ellen is really something. She's got my attention now. The book is gone and I am trying to make up for two years squandered on reading. From time to time, I ask my wife to fill me in on what has happened before. I am in a constant state of being shocked.

The show concerns a family named the Ewings who live on a ranch called South Fork, which is a combination of Tara and the Persian Gulf. The Ewings have thousands of head of cattle you never see and oil wells you never see and two or three Mercedes you do see. You also see them having breakfast together and fighting, which is the way they start the day in Texas.

My favorite character is the aforementioned Sue Ellen Ewing. She has had an affair with just about everyone. At the moment she is having an affair with a cowboy who I think is the heir to a mighty fortune and not the drifter he pretends to be. I'm not sure about that, though. I was reading when all of that got explained.

Anyway, I know for sure that Sue Ellen cries most of the time and she had an automobile accident with her baby. It is her baby, but not her husband's baby. In this program, this is a technicality. I'm told she and her husband never have sex although I'm also told that he's having an affair with his secretary. My wife tells me that his secretary is Sue Ellen's sister. Now you know why I'm shocked all the time.

The father of Sue Ellen's baby is Cliff Barnes. He is the son of someone named Digger Barnes whom I have never seen but who is a mortal enemy of the Ewing family. I have seen enough of the show to know that mortal enemies are made of other people in the cattle business, other people in the oil business or anyone who once courted Miss Ellie and lost her to Jock Ewing who got her, the ranch, the cattle, the oil and, in due course, the Mercedes cars.

Sue Ellen goes shopping a lot. She also drinks a lot and, according to my wife, she was also once a drug addict. (It's a wonder she has time for affairs.) My wife also told me that the baby Sue Ellen had with Cliff Barnes did not have the rare blood disease peculiar to the Barnes family. This, I have to tell you, was some relief. As a result of all this shopping and drinking and doping and mucky-nook-nook in tacky hotel rooms, Sue Ellen is seeing a shrink three times a week. Her husbank, J.R., characteristically calls this "telling a stranger family secrets."

J.R. is one of two brothers. The other brother is Bobby. He is very handsome and never wears his tie up to the collar and blow-dries his hair. J.R. and Bobby do a Cain and Abel number. Bobby is the good guy, but J.R. is the better actor. I hate him. He lies to Poppa and he lies to Miss Ellie but then everyone lies to Miss Ellie. It's a wonder everyone fought over her when he was younger. She cries a lot, too.

Bobby has a wife. She is also the sister of Cliff Barnes and up to now she has not had an affair with anyone -- even her brother. Either that, or my wife is protecting her. There is also a granddaughter. She is blond with very long hair but the truly amazing thing about her is that while she has grandparents, she does not seem to have parents. They are off somewhere with the cattle and the oil wells.

The granddaughter cannot drive. The reason she cannot drive is that she has a tendency to get drunk and crack up cars. (This all happened before I started watching. God knows how many Mercedes they once had.) She also has affairs with cowboys -- a family failing. Right now, though, she is putting the make on a double agent planted by J.R. in the campaign of Cliff Barnes who, as some sort of official, has stopped the Ewings from drilling for more oil. J.R. figures that Barnes would be powerless if elected to Congress. J.R. may be mean, but he is no fool. Either that or he once lived in Washington.

Anyway, it is clear by now that "Dallas" is our very own "Upstairs Downstairs." All the time that British masterpiece was on the tube, people kept asking why we in America could not do something as good. People kept saying that our writers couldn't write as well and our actors couldn't act and commercial television would just never do anything really terrific.

With "Dallas" though, we have our own version of "Upstairs Downstairs." It's indigenous, it's well written, it's well acted and it's dirty as hell. The chief difference between the two shows is that in "Dallas" everything takes place at breakfast, not at tea, and there is no downstairs in a ranch house. There is another difference. "Dallas" does not have Alistair Cooke to introduce it.

I'd love to see him explain Sue Ellen.