Now don't get too excited, Washington, but St. Alban's Tennis Club just may be coming into the 20th century. Yesterday in a notice to the exclusive membership the management conceded that "members who have a non-marital living arrangement with another person still have club privileges. However, the person with whom members are living cannot have guest privileges. Couples must be listed under member's name." Now most people think that means if you're shacking up with somebody you can still use the club but don't try to bring in friends on your own steam. Got it? St. Albans, incidentally, has probably held together more lousy Washington marriages than the Joy of Sex. Mainly because it's easier to get custody of your children than custody of your St. Albans membership. How you get a membership is simply to send your kid to St. Albans, be famous or both. New members this year include: Michael Blumenthal, Warren Christopher, Cy Vance, Richard Valeriani, Bobo Legendre, Margaret Osmer, Robert Pierpoint and Howard Metzenbaum.

DO DO DEE DO DO . . . So what's with The Wall Street Journal's Al Hunt and NBC's Judy Woodruff? . . . Hugh Scott seen stopped by two cops Friday morning - Hugh, dear, you simply must get those license plates on your car . . . Pat Caddell has the cutest new hairdo - makes him look almost 30 . . . On a recent plane trip FBI Director Clarence Kelley was seen totally absorbed in the inflight movie, "Thieves" . . . Hamilton Robinson paid $450,000 CASH for Dick Shapiro's house at 3263 N St. . . . If you're dying to get Griffin Bell's autograph try Romeo and Juliet's - he hangs out there a lot . . . Tandy Dickinson is housesitting this week in London for you-know-who . . . Bert and LaBelle Lance aren't paying much attention to Jimmy - one night last week every light in their Georgetown house was blazing . . . Jack's daughter, Joy Javits, is teaching graduate dance at the University of North Carolina . . . Deputy White House press secretary Rex Granum had a big week last week - got his pix in Newsweek for the first time and then had his '69 Mustang ripped off - Moral: Rex, darlin', you just can't have it all . . . and if you think Jackie Kennedy had entourages when she traveled, check Rosalynn's South American crew: press secretary Mary Hoyt and her secretary, Faith Collins, personal assistant Madeline MacBean and her personal secretary, Carol Bennefield, appointments secretary Jane Fenderson, press advance Barbara Heinebeck, White House nurse Karen Noto PLUS Rosalynn's hairdresser, Eivind Bjerke. Is anybody staying home?