What was going on when I was born?

As one character says to the woman he has just seduced and been seduced by, who happens to be his closest friend's roommate and lover, ''The actual facts are so simple. I love you. You love me. You love Otto. I love Otto. Otto loves you. Otto loves me. There now! Start to unravel from there!'' And so Noel Coward did, spinning out a characteristically brittle and breezy confection of wit among the privileged and neurotic in ''Design for Living.'' The play, which he wrote for himself and Alfred Lunt and Lynn Fontanne, opened on Broadway in 1933. Brooks Atkinson of The New York Times noted that its subject matter could be termed ''decadent,'' but the play was well received in New York, although its English debut was delayed until 1939 because of the Lord Chamberlain's objections. The menage a trois that shocked and titillated in 1933 might scarcely raise an eyebrow in these jaded times. But despite the passage of half a century and a resurgence of interest in the late Sir Noel and his works, ''Design for Living'' has never been revived on Broadway - until now. On Wednesday, the play will open at the Circle in the Square, starring Jill Clayburgh, Raul Julia and Frank Langella. George C. Scott is directing the production.

THE KENNEDYS An American Drama. By Peter Collier and David Horowitz. Illustrated. 576 pp. New York: Summit Books. $20.95. By Ted Morgan STRIP the paint and you get down to the wood at the risk of finding the wood wormy, which is what Peter Collier and David Horowitz have done by stripping the layers of myth from the Kennedy family history. Mr. Collier and Mr. Horowitz, the authors of an excellent book on the Rockefellers, have done this by circumventing ''the Kennedy Damage Control Department,'' which sponsors a literature of apology by courting friendly authors into writing congenial versions of the tale. One is reminded of Piero della Francesca's commissioned portrait of the Duke of Montefeltro. It was painted in profile because the duke was blind in one eye. ''The Kennedys'' is a full-face family portrait based on a phenomenal amount of freshly harvested research that its subjects will not find flattering. It is a portrait of four generations, with the feel of lives progressing through historical time that one finds in such multigenerational novels as ''The Forsyte

In the beginning, maybe eight years ago, the new David Rabe work for theater was a thin sheaf of notes filed under the heading of ''the guys' play.'' It was born, probably, out of his first brief chaotic stay in Hollywood, but Mr. Rabe is skittish about stressing the connections. From time to time, a striking piece of dialogue would swim into his head, to be noted and dropped into the folder which, even so, hardly grew. Then, in 1982, two events altered his life: His daughter was born and his best friend died. Without quite understanding why writing the play had become so urgent, he sat down to the typewriter early last year and in a couple of months, record time for a famously slow worker, had a draft of what has become ''Hurlyburly.''

The State Department has asked New York City to bar Libyan diplomats from occupying that nation's nearly completed 23-story East Side headquarters, pending clarification by the Government of Col. Muammar el-Qaddafi on how the building will be used. Repeated requests for information from the Libyans on the use of their $20 million tower at 309 East 48th Street, near United Nations Plaza, have gone unanswered, a State Department spokesman said yesterday. The State Department requests have come amid mounting concern in Washington over state-sponsored terrorist activities. Until the Libyans provide a satisfactory response, the spokesman said, the State Department has asked the city to withhold a certificate of occupancy for the building, Libya House, which has been under construction since 1980 and is scheduled to be finished next month.

RONALD PARENTEAU says that when he tells people he lives in Georgetown, it starts all kinds of conversations because he has to explain that it is not really one town, but a community that includes parts of four towns. ''I kind of like saying I live in Georgetown,'' said Mr. Parenteau, a resident for 25 years. The community with a claim on Mr. Parenteau's affection has a fire district, a telephone exchange and a ZIP code. What it will not have after the end of September is the post office in Gianvincenzo Marsili's building on Old Mill Road. Mr. Marsili told the Postal Service about three months ago that he would not renew the lease. According to the Postal Service, it is looking for another place for a post office, but the 489 residences and businesses getting mail delivered from the Georgetown post office will have to change their addresses or pick up their mail themselves.

HOUSTON THE object came upon him too suddenly, too fast. It was a nightmare, a split second that broke into years. His mind could not reel quickly enough to catch up with the baseball striking him in the head. He spiraled in the nightmare, gasping, shuddering, down some steps, clawing for something, someone, who could lift him up. Dickie Thon remembered that then he was on his back, the baseball hero crumpled in the batter's box. He realized later that the crazy, hurried thoughts to stop the baseball from hitting him had not occurred until after he was hit. He realized the moment was not that complicated. The pitcher's fastball ran in on him and he, so intent on watching it, hardly reacted, reacted only as he had been taught, to hang in there.

LONDON From the beginning, the challenge in filming ''Sakharov'' was how to portray an enigmatic but courageous man caught inside a secretive and totalitarian state. What caused Andrei D. Sakharov, the physicist credited with developing the hydrogen bomb for the Soviet Union, to be driven by conscience into a repudiation of nuclear arms? What motivated him to become an outspoken human-rights advocate in a state that does not suffer dissent or ingratitude kindly? And how could moral authority be packaged within a two-hour dramatization that attempts to avoid the pitfalls of Cold War cliches about saintly figures being persecuted by state inquisitors? How successful the filmmakers have been can be determined Wednesday evening at 8 when Home Box Office will present to its subscribers ''Sakharov,'' starring Jason Robards in the title role and Glenda Jackson as his wife, Yelena G. Bonner. (A special screening of the film for Government officials and human-rights activists will be held the night before at the Kennedy Center in Washington.) Originally planned to be shown on the pay cable service only in September, the film has been hurriedly inserted into HBO's June schedule for a single advance presentation in an effort to draw attention to the plight of the 1975 Nobel Peace Prize laureate and his wife, herself a noted human rights activist. Concern about the couple has heightened recently as conflicting reports circulate about the state of health of Dr. Sakharov, who this spring vowed to ''fast to the very end'' if Soviet authorities did not permit his wife to go abroad for medical treatment of a heart condition.

Some unusual partnerships between churches and real-estate developers are being formed in the metropolitan area, creating new housing and, in some cases, providing new sources of income for the churches. In two projects in Connecticut, churches are playing a particularly unusual role, developing retail and office space as well as housing. In Stamford, St. John's Episcopal Church has contracted with the Lafayette Development Corporation to build a mixed-use project on its land in the city's downtown urban-renewal district. And in Greenwich, St. Mary's Roman Catholic Church is a principal in a $12 million office and retail project to be created on church land. Some churches have encountered difficulties in their realty enterprises in the form of local landmark- preservation laws, which restrict their ability to develop or sell their properties. Just last week, for example, the New York City Landmarks Preservation Commission ruled against a proposal by St. Bartholomew's Episcopal Church to sell its air rights and part of its property to a developer who would build a 59-story office tower. Such considerations have not been a factor in the two Connecticut undertakings.

Hale Irwin and Fuzzy Zoeller waged a memorable head-to-head battle for 18 holes in the third round of the 84th United States Open at Winged Foot's West course today, with one or the other holding a one-shot lead in the tournament on six occasions. Finally, it was Irwin who got the last lead of the day when he parred the final hole for a round of 1-under- par 69, his third straight sub-par round of the championship. This gave Irwin a total of 205, five under for 54 holes, on the 10th anniversary of his first Open triumph, also here at Winged Foot. Zoeller started the round in second place, one shot back of Irwin. He ended it in the same position. Zoeller hit his approach at the 18th into a bunker and had to settle for a bogey 5, which gave him a 69 and a three- round total of 206. Zoeller had also bogeyed No. 17 to fall back into a tie with Irwin for the sixth time in the day.

A few hours after the Mets released Mike Torrez, their oldest pitcher, Dwight Gooden, their youngest one, threw seven efficient innings to win his sixth game of the season as the Mets defeated the St. Louis Cardinals, 4-1, at Busch Stadium tonight. The victory was their fourth straight and the 11th in 13 games for the Mets, who maintained a half- game lead over the Phillies and opened a game and a half lead over the Cubs in the National League East. Before the game, the Mets designated Torrez for reassignment, in effect dropping the right-handed pitcher from the roster. The Mets acquired Bruce Berenyi from the Reds Friday, and Torrez became expendable. Gooden, the 19-year-old fastball artist, struck out three batters and faced only 29 before giving way to Jesse Orosco with two out in the eighth. Orosco finished the game for his 13th save.

As the Seabrook 1 nuclear power plant sits dormant on the New Hampshire coast, three-quarters complete but on the brink of cancellation because of cost overruns, New England utilities are shopping here for alternative power. The Canadians say they are willing to provide it by what they see as the most economical and reliable means: nuclear power. The New Brunswick Electric Power Commission says it is prepared to build a nuclear plant whose entire output would be sold to New England utilities for 20 years at slightly more than the cost of production. ''I think we can be competitive in the market, supplying power under terms and conditions acceptable to purchasing utilities,'' said Richard Cote, general manager of Maritime Nuclear, a joint venture of New Brunswick Power and Atomic Energy of Canada Ltd., the federally owned reactor-building concern. Meeting the U.S. Market ''In the future, you wouldn't have to stretch the case too far to say you could build units in the Maritimes to meet the market in the U.S.,'' Mr. Cote said in an interview at his office here.

A S though making up for lost time, the House last week took up a broad immigration control bill and moved briskly through more than 50 amendments. By week's end, the debate still hadn't ended, but many opponents of the measure had begun to talk of the inevitabiliity of passage. ''Things don't look very good,'' said Robert Garcia, the Democrat from the Bronx who heads the Hispanic Caucus.