Bob Evans, the mayor of Washington Grove, Md., and his wife, Kathie, had some friends over for a barbeque one night this week.

Everyone drank gin and tonics and sat in the backyard relaxing, chatting and enjoying the cool breeze, the clear sky, the smell of hamburgers grilling. If Norman Rockwell had painted a portrait of "suburban idyllic," he would have come here for the model. "It's our version of paradise," said B.J. Hargrove, one of the guests.

Everything was proceeding quietly, calmly, until the Evanses' 6-year-old daughter, Sarah, came sprinting up to one of the tables, poked a man on the arm and asked:

"Are you one of the Russians? Are you? Are you?"

Yuri Denisenkov just smiled, waited for the translation from Valentina Tribunskay, and answered:

"Da."

Everyone laughed, for throughout Washington Grove -- a tiny Maryland town with 2.8 miles of road and an $80,000 annual operating budget -- 35 honest-to-Lenin Soviets, who are visiting America for a series of conferences sponsored by the Forum for U.S.-Soviet Dialogue, lodged this week in the homes of well-to-do families. Although many members of the delegation were officials for the Communist Youth Organization, the group also included a wrestling coach from Alma-Ata, a composer from Leningrad and member of the Supreme Soviet from Kazakhstan who lists her profession as "tailor."

Tuesday is Lady's Night at Bogart's, a bar and restaurant decorated with Humphrey Bogart memorabilia. Bogey statues, Bogey portraits. For the Americans -- bronzed young men and women dressed in polo shirts and lots of khaki -- it's Singles City. For the Russian delegation drinking at a private bar in the back after the long flight from Moscow, it was time for some cheer and unloading on Lee Highway.

Twenty Soviets had arrived at Dulles a few hours earlier -- the rest of the delegation would have to wait another day in Moscow because of snarls caused by the air traffic controllers' strike. The Soviets bellying up to the bar looked a great deal like the Americans around them, and managed to suprise the waitresses with their orders -- nary a vodka drinker in the lot and not a single Black or White Russian. "They were very big on Heinekens," said Debbie Kidwell, one of several waitresses in Hawaiian shorts and shirts who served the delegation. "Oh yeah, they also went for pin a coladas, gin and tonics and scotch."

They followed that up with a fixed menu of Americana: prime ribs, baked potato, salad, and burgundy served in a butcher-block-and-plants setting. Before anyone touched a morsel, though, Greg Fess, a Department of Energy counsel and a forum board member, set the pattern for the evening.

"A TOAST!" While everyone had been chatting away bilingually, the waitresses quietly filled tumblers to the brim with cool, clear Stolichnaya. More than one of the Russians ignored the vodka and stuck with the wine.

"A TOAST!" One after another, more than a dozen Soviets and Americans rose to pay tribute to everything under the sun. Bill Lassard even blessed the Soviet Communist Party: "SLAVA K.P.C.C." By evening's end, six bottles of vodka lay drained on a shelf somewhere. Through it all, the Russians remained perfectly lucid.

At dinner, everyone tried to accentuate the positive. Sergei Kolesnikov, an administrator at the Institute of Clinical Medicine in Novosibirsk, talked about life in the land of six-month winters: "Siberia is a great opportunity. It is wonderful. Really."

Denisenkov, like everyone else within earshot, urged better relations between the two superpowers but let his guard down a little to take a shot at his hosts: "Along the highway we saw many billboards advertising all different automobiles. Some of them American."

A muscular ex-wrestler and teacher of Urdu, Sergei Beznosenko, looked glazed from his long trip. He didn't touch his salad. He refused his prime rib. And when a concerned waitress brought him a melted cheese concoction instead, he poked at it once and looked glumly away. As for the trip so far, he said, "I guess I should say I like it very much but right now I'm very tired."

Before they boarded their rented Metrobus, the Soviets disappeared into the thicket of the dance floor and a few Bogart's regulars commented on the restaurant's newest customers.

Mike Moran stood by the bar and watched the weaving action before him. "Let's put it this way," said the powerfully built Moran. "I'm ex-service, ex-military, okay? They're people just like we're people. What it boils down to is this, okay? They wear their pants just like we do and their women dress like ours. Okay?"

Another customer, who would not give his name, said he knew that "10 or 12 regulars" who work at the CIA stayed away because they knew the Russians were coming to Bogart's. Otherwise, he said, they would have been forced to report their contact with the visitors to the agency.

Feelings, the group sending out the funk on the dance floor, finally knocked off and Bogart's owner, Evan McConnell, came running back to the bar sweating and yelling:

"The Russians! You should have seen them! They were jamming!"

Tuesday night, the delegation stayed at a hotel, but Wednesday, after making stops at the White House, Alexandria and Dulles (to pick up the rest of the group), the Soviets arrived in Washington Grove for the big welcome.

A huge banner hung from a fence around the town tennis courts: "DOBRO POZHALOVAT DOROGEYE SOVETSKI GOSTI!" ("Warm Greetings, Dear Soviet Guests!") As the delegation stood by the bus, a rag-tag, no-uniform, 13-member band struck up the Promenade from "Pictures at an Exhibition" and "The Great Gates of Kiev." The tuba sounded a little off, or maybe it was the tuba that was on and the rest of the band off. In any case, said trumpeter Steve Ayton, "We just practiced once."

The delegation outnumbered the welcomers, but the Soviets seemed grateful nonetheless. After the band finally polished off "Happy Days Are Here Again," Anastasia Nazaruk, accompanied by Ion Teodorovich, led the group in a few Moldavian folk songs. While she sang about the birds of Moldavia, some, like Tom Bresnahan, waxed nostalgic about the last time a similar Soviet delegation came to town. "It was the same when we had them two years ago," he said standing in the plush park grass. "When you have a town as small as this, you can provide a kind of family atmosphere."

Were any people in town upset about the Soviets coming?

"There are some people around town who say this is a sham. They think it's meaningless," said Kathie Evans. "One of my friends thinks we're going through a charade when neither these Soviets nor us as Americans make any real political decisions. But nobody seems real negative like 'I wouldn't have any of those Russkies in my house.' "

When Nazaruk finished singing "Vesna" ("Spring"), Greg Fess matched up the names of the host families and their guests.

"Sue Grable! Nazaruk and Tcherneschov!"

"Tannenbaum! Shakai and Kamblayavichus!"

Introductions were made.

"Hello, my name is Vladimir."

"I'm Caroline."

And so the attorneys, accountants and scientists of Washington Grove took in the the Soviets. While Bob Evans sat at his kitchen table waiting for Alexander Barchenkov and Vladimir Egorov to freshen up, he set aside the politics of detente for a moment and talked about what many think about in these situations: the KGB.

"I'm sure there are members of this delegation who are from the KGB," said Evans. "Last time the Russians were here Forum Board member Greg Fess was pointing out all the agents."

"That's right," said Kathie Evans, shutting off the sink for a moment. "I think people just accept that the KGB is acting as baby sitters. Everyone found it more humorous than threatening."

Sarah, the Evanses' irrepressible daughter, interrupted with a question about her new doll.

"Daddy, how much did it cost?" she said with an impish grin that suggested she already knew a thing or two about propriety. Her parents could only hope she would avoid the subject of neutron bombs during dessert.

"Sshhh, honey, not while Daddy's talking."

The mayor continued: "Whether there are KGB agents here or not, we think that with people like this coming here, with everybody showing friendship, maybe we will soften ideas about 'the enemy.' I have to believe that this group of people is very carefully selected -- for a variety of reasons -- and that they will eventually be in some positions of leadership one day. So this just might help. KGB or not."

Later on, Greg Fess said of KGB involvement, "It's not unlikely, but I have no reason to believe anyone here is an agent. I've never been approached by anyone for any surreptitious reason that would indicate they were interested in anything more than this program."

"We're having hamburgers, an all-American meal," Kathie Evans told her husband. "Don't tell our guests, but the Ericksons are having filet!"

Barchenkov, a teacher of English and Finnish in Moscow's Foreign Languages College, emerged from the guest room. He walked through the book-lined, paneled living room and into a gleaming modern kitchen. He sat at the kitchen table, took a sip of Molson's Ale, looked out the window at the setting suburban sun and said, in perfect London-learned English, "It's great, really wonderful here. A beautiful area."

And then everyone dug in.

After polishing off a couple of burgers and a mound of potato salad, Yuri Denisenkov leaned back and savored his Giacobazzi. "These exchanges can break certain stereotypes," he said looking off into the trees. "When I first came to America I probably did have a stereotype of a very enterprising people but real life did not adjust to this stereotype. For most Americans this enterprising is not really the most important part of their lives."

Denisenkov, like the others, insisted the Reagan administration's hard line with the Soviets was "not productive. Of course, President Reagan and his administration do exist, but the ordinary people exist aside from his opinions."

It seems, though, that Reagan is very popular, Yuri.

"You mean seems?" said Denisenkov. "Or is popular."

Thursday night the Communication Workers of America hosted the Soviet delegation at the International Club for a reception and a filet mignon dinner. The featured event of the evening was Walter Mondale's translation race with Alexander Barchenkov.

Mondale, the guest of honor, said he knew the Soviets would bring home good will as they traveled to cities like New York, St. Louis, Chicago, Washington, and while Barchenkov struggled to keep up, Mondale threw in his favorite city, Minneapolis.

That brought the house down.

Later CWA president Glen Watts interrupted Mondale while he was speaking at the podium. "Even at this dinner, presidents interrupt vice presidents."

Yesterday afternoon, part of the delegation visited a Mack truck plant in Hagerstown, while the three Moldavian musicians in the group and Sergei Deznosenko visited a recording studio and stopped for lunch at McDonald's. "Hot dogs. Pepsi. A very good snack, I believe." said Deznosenko. Singer Anastasia Lazaruk looked out of the Evanses' Buick window while riding along Canal Road and asked in Russian, "Just how much is land worth in this area?"

When she was told, she looked about as shocked as any other perspective land buyer in Washington.

The Soviet delegation wrapped up its stay in Washington Grove last night with a potluck dinner and a sing-along held in an octagonal town hall that looks more like the dining hall of Camp Granada than a governmnet building. At picnic tables set up outside the hall, townspeople and their guests drank keg beer and lined up for a feast of casseroles and lasagna.

Grandparents nibbled tuna casserole and Jell-O in one corner, tiny children wearing enormous straw hats ran wild, Russians and Americans of all ages exchanged addresses and, with the help of a translator, a few laughs and heartfelt goodbyes.

After dinner, guitarist Teodorovich, accordionist Nikolai Botgross and singer Lazaruk--all in native Moldavian rubashki--performed for the crowd. THe Russian was a little tricky, but in the "Ah ya ya ya ya" parts the Americns sang along like true Moscovites. And then, though she can hardly speak a word of English, Lazaruk stunned the crowd into silence with the Barbra Streisand hit, "A Woman in Love."

After the show, the Soviets and their hosts trailed back to the houses together one last time. Later today, they'll arrive in Lockhaven, Pa., for a week of conferences and then it's back to the U.S.S.R., airplanes willing.