A DIVORCED FRIEND who survived three teenaged daughters used to wonder why they never had high school parties at their home. She was convinced it was because they were ashamed of the house. Not long ago, she found out they weren't ashamed of it at all. In fact, they loved it so much they did not want half the high school crashing a party and wrecking it.

Graduation and warm weather mean the teenage party season is upon us and we'll probably be hearing a lot about wild gatherings for 500 in the countryside and hordes of partying teen-agers vandalizing private homes. But it doesn't have to happen.

Last weekend, Nina McCormick of Chevy Chase threw a graduation party for 300 of her closest friends in her home and she and her parents are still speaking to each other. There's more. Her mother, Alberta McCormack -- despite the condition of the floors and the rugs and the pilfered banister finial -- goes so far as to say the party was "a good thing and I'm glad we did it." It succeeded, she says, with a lot of planning and a lot of chaperoning, which Nina wanted as much as her parents. It is still p ossible, in other words, to have a large teen-age party that works.

"I talked to every parent that I could who had had large parties, either successful or unsuccessfull," says Mrs. McCormack, to find out what they had done right or wrong. "And my daughter assured me that the times when drastic things had gone wrong . . . were times when there had been no adults present. The stories of chandeliers ripped out of the ceilings, the holes in the walls, the paintings slashed, were times when nobody was in charge. And she also assured me that the people she essentially wanted to invite were responsible people.

"What we worked through and what we tried to help her understand was that even though you try to control things, the minute the word gets out . . . it is very difficult . . . to control who comes.

"We decided to try to compromise on things that she felt strongly about but were of medium importance to us, but be very firm about the things that our gut instinct told us were essential in spite of her objections." They decided to serve beer since most of the guests were 18 and they recognized that the kids would be driving back and forth to the store to get beer if they didn't serve it. "That didn't seem like a very good thing . . . But we also agreed to have soft drinks and a fruit punch."

Along with the beer, they served 300 sandwiches, cold cuts, cheeses, rolls, numerous dips and a lot of popcorn, and birthday cakes at midnight for a guest who turned 18. "We knew that if kids were going to be drinking and didn't have a good base to eat, there would be a lot of people who would drink too much."

Before the party, Mrs. McCormack visited all the neighbors to tell them it was going to take place and that the music would be turned down at midnight. iShe also informed the police that there was going to be an authorized party at their house.

"As far as the music went," we had no outside speakers," says Mrs. McCormack. "We used just our living room stereo and opened the door adjacent to it so the music could drift outside. I knew that wouldn't get overwhelming in terms of the neighborhood." A guest ran the stereo, which kept some order to the music, and protected the equipment.

The McCormacks protected valuable shrubs and nursery stock with chicken wire and roped off areas where they did not want the kids to walk. Since they do not have a family room or recreation room, much of the party was in the living room and dining room. They protected valuable furniture and the piano with plastic. "Our rugs needed cleaning anyway. I wasn't quite prepared for the amount of beer that got spilled on the floors but they needed a good going over anyway," says Mrs. McCormack.

"In addition to my husband and I being there, we hired three chaperones -- two men and one woman friend -- to help us, not necessarly in a bouncing capacity, but to be our eyes in different places where we couldn't be. They were friends of ours who are over 28, who have children of their own, and what I consider a parental point of view.

"I met with them beforehand. We walked around the property and talked about what things we were willing to tolerate and what things we were not willing to tolerate. We said, for instance, there could be no smoking of any kind in the house, just as a fire hazard and to avoid the business of cigarette butts being ground into floors and carpets." The chaperones walked continually around the house and property during the party.

Nina McCormack sent out written invitations two weeks before the party to about 210 people. There were people who crashed, says Mrs. McCormack, "but we had generally decided that if people behaved themselves, unless it was a dangerous press of people, whoever was here would be allowed to stay."

Even though they provided beer, a very few people brought hard liquor. "We relied more on the aspect of how people were behaving than what they brought," says Mrs. McCormack. "One fellow even brought a large bottle of Perrier water and wanted to put it in the bottom of my refrigerator to keep cold. The fact that there were seven bowls of just pure fruit punch [and 30 quarts of soda] consumed meant not everybody was drinking.

"My daughter felt absolutely sure that those things were absolutely ridiculous, that everybody was going to drink. But we remained firm about this. She was absolutely amazed [at the amount of punch and soda consumed]. t

"The invitation said 8:30 to 1. People began to drift off anytime after 12. They really began to leave mostly at 2 and the last person left at 3. I was torn about whether to really close up and invite people to leave after 2, but since I overheard so many people taling about not going home but going on to their places I thought from a safety standpoint, it makes more sense to have them stay here and hopefully they'll be tired enought to just go home.

"Many of the kids said it was the best party they'd been to ever, and thanked us for having it and said the eats were terrific. The next morning some of the teen-agers came back to visit me at 11 and find out how I was and how the house was and to make sure everything was all right."

Nina McCormack, who will be going to Middleburg College in Vermont this fall, was horrified when her mother began putting away valuables and covering the new piano in the living room with plastic. "But nobody noticed," she says now.

"The most important thing," says Nina McCormack, "is to have your parents there and responsible people around. I've seen so many kids have parties when their parents are out of town and antiques get broken and mirrors get smashed or somebody walks through a window.

"I had a fantastic time. My mother put a whole lot of work into it, and it would not have been possible without her cooperation. It's about the biggest present anybody's ever given me."