THE NAME FIRST surfaced a couple of months ago when the resident 13-year-old came home from shcool, flopped on a sofa and started flipping through the paper to the movie ads. Finally he found what he was looking for, and chin in hand, settled in for a prolonged stare. At last he emerged from his reverie and looked up.

"10," he said.

"What?"

"10." A distant look came into his eye. "Bo Derek."

"Who?"

His voice tight with impatience: "Bo Derek, mother. Don't you know anything?"

Me, in icy tones: "Apparently not. Who is Beau Derek?"

He showed me the ad. Light dawned. Beau was not a man. Bo was a woman. A perfect woman. A "10."

I learned long ago not to believe movie ads, and decided to ignore Bo Derek. But, have you tried to ignore Bo Derek lately? It's impossible. Every newspaper or magazine you pick up these days has something about Bo Derek. And what's worse, they also have articles on Bo Derek's husband. Now you might ask at this point why I and 18 million other American women are wasting our time reading these articles, and it's a good question. All I can say is that after reading one article about the Dereks, I was hooked.

Bo, it seems, was 16 years old when she met John Derek. Her name was Mary Kathleen Collins. She was a high school dropout. He was producing a film in Greece. He was also married to Linda Evans. Everyone went to Greece and Bo costarred in the film. She starred in John's life. Or, as the Ladies Home Journal puts it, Derek "found himself holding hands with his leading lady. When Linda left Greece, Bo and John soon became inseparable."

There was a tensy problem, however. Bo was a minor. John was in his late 40s and considered an adult, legally. The United States has tacky little laws like the Mann Act and statutory rape laws. So John and Bo resolved that problem by traveling abroad until she grew up and they could return here.

Now, back in the '50s this is the kind of stuff that could destroy a movie star's career if Louella Parsons ever got hold of it. Overnight. But times have changed. Far from trying to keep their early liaison to themselves, Bo and John apparently talk quite openly about it. The Ladies Home Journal tells us that Linda was "heartbroken" over the turn of events but she must have gathered herself together. According to Tuesday's Washington Post. It was, you guessed it, Linda who researched the legal situation "before John and Bo returned to be married."

Linda, Bo and John and Ursula, another ex-wife, all get along. Bo tells the Journal: "At John's birthday party last year Ursula and Linda and I all wore T-shirts with his photograph on them. It was a lot of fun and very relaxing. John still loves Linda and Ursula, too. And they love him as well. It's like an extended family, though, of course, he's no longer intimate with either of them."

Linda is an actress. So is Ursula. John took pictures of Ursula and Linda in the nude and sold them to Playboy. He took pictures of Bo in the nude and sold them to Playboy.

John Derek, former actor and now a movie producer, has found a terrific way to make pin money. It seems he finds beautiful women with pliant personalities who don't mind being photographed without their clothes on. We are told by Ladies Home Journal that Derek "dictates almost every element of his wife's life."

John Derek has taken over Bo, just as he took over previous wives, exploiting their bodies, their faces, and whatever acting talent might be there. And everyone is acting like this is all right, like this is a perfectly proper way for a 53-year-old man to behave.

I'm sorry, but it is not. Derek comes across as a revoltingly self-centered, overbearing man, a man who has dangled the brass ring in front of a teen-age girl and gotten her to do whatever is necessary in order to grab it. If he runs afoul of accepted behavior in society, well, he just changes and moves into another society for awhile. He deals with such issues as nudity with the profound observation that God didn't make Bo with clothes on. There is a decadent quality to the season's fun couple, a quality I'd hoped we left back in the '70s at Studio 54.

But, Bo Derek is IN, no question about it. Bo Derek's braids are IN. Ladies Home Journal is touting her as the sex symbol for the '80s. She certainly won't make it as a symbol of independence. Bo has thrown in her lot with Derek; she has allowed herself to be molded to his specifications, as Ladies Home Journal put it, he has guided every step of her career and personal life, and she is probably going to end up making oodles of money.

Not bad for a high school dropout. She must figure the price is right, but I can't help feeling after reading the articles that she should have stayed in school.