Every once in a while, there's a Washington party where people don't rubberneck to see what famous person is bursting in next. And last night at an outdoor "Stanley Stomp" dinner dance that Republican super-insider Robert Keith Gray gave for fellow insider Nancy Reynolds, that's what happened.

Maybe it was because it was too dark to see. Maybe it was because it was cold. Or maybe if you get a Washingtonian out of Brooks Brothers and into black lizard boots (Sen. Paul Laxalt's R-Nev. evening footwear), he acts like a normal party guest.

"This is a free-wheeling, successful party," decreed Letitia Baldrige, the New York etiquette expert who came down for the stomp. "The only etiquette is please don't spill your entire drink down somebody else's front."

The western-style party for 300 was on a brick terrace just outside Gray's public relations office, housed in the Georgetown building whose mailing address is simply The Powerhouse, Washington, D.C. For the evening, Gray named the terrace "Powerhouse Square." This prompted one snippy guest to remark that, in reality, "it's been Fishmarket Square for 200 years."

Few others quibbled. Besides, there was a lot to do. Like eat. Ribs, potatoes, beans, hot cider, guacamole, barbecued chicken, beans, pumpkin pie, kiwi fruit, corn muffins. Even browsing was fine.

Reynolds, as all of social-political Washington knows, knows everybody, most significantly Ronald and Nancy Reagan. And from way back, which is really significant. Gray knows everbody, too, and was also co-chair of the Reagan inaugural. More important these days is that he's known for giving some of the best parties in town. (Last summer, for instance, he had an outdoor, black-tie dinner for Laxalt right at the foot of the Capitol.)

Naturally, Reynolds and Gray know each other. In fact, they're even friends.

Some of the biggest names in town came. Such as: presidential counselor Edwin Meese III, congressional liaison Max Friedersdorf, Attorney General William French Smith, Commerce Secretary Malcolm Baldrige, deputy secretary of state William Clark, presidential assistant Helene von Damm, Moroccan Ambassador Ali Bengelloun, the first lady's press secretary, Sheila Tate, East Wing staff director Peter McCoy, presidential daughter Maureen Reagan and Sarah Brady, wife of the recuperating White House press secretary.

And there were plenty of Reynolds' friends from her home state of Idaho, which gave the party a just-plain-folks feel. There were also some of the younger reporters and White House staffers that Reynolds has befriended. Everybody wore western gear, sat on bales of hay and valiantly tried to dance what Reynolds and Gray called the Stanley Stomp. This is a square dance they do in Stanley, Idaho. The people of Washington probably didn't get it exactly right, but who could tell?

"You know, friendship with Bob is a dangerous thing," said Reynolds. "Five years ago, I said, 'Gee, I wish I could bring a bit of Idaho to Washington and have a Stanley Stomp.' And he did it."

Maureen Reagan seemed particularly suited for the Stomp, dressed as she was in cowboy hat and leather fringed jacket. She's thinking about running for the California senate, even though her father said at a press conference this summer that he hopes she doesn't.

"My response was that he was stealing my lines," she said. "That's what I said in 1975 when he wanted to run for president."