Where is the mother of a 12-year-old who doesn't remember turning off an early-rock Lothario with: "Just because I like to dance with you, doesn't mean . . .

In "Saturday Night Fever," the movie starring pre-teens heart throb John Travolta, the make-out wheel has come full circle. Girls, complains Travolta in his role as disco dancing king Tony Manero, "think that just because you make it with them, you gotta dance with them."

Thus the rending question confronting families this summer: Should you let your 12-year-old, the one who has idolized John Travolta as the lovable hellion Vinnie Barbarino on television's "Welcome Back Kotter," see Travolta as Tony Manero in "Saturday Night Fever"

The youngster have all heard about Travolta's dancing, they've consumed or been consumed by the Bee Gees music all spring on the radio and now they are pestering parents to see the movie which they've heard is "great." In the patois of the 12-year-old set, there is no better superlative then "great."

Most parents, by this time, have heard that "Saturday Night Fever" may be great, all right, but that it is loaded with four-letter word, heavy sex and violence. There is, in other words, a reason for the R-rating that requires children under 17 to be accompanied by adults.

What parents say to the 15-year-olds and up about whether they can see the movie or not is probably irrelevant since they will do what they want anyway. But it is relevant to the younger children, the ones who started watching Vinnie Barbarino three years ago and have-idolized him ever since. What do you say to them when they plead with you to let them see "Saturday Night Fever"?

You can say no, and then say why, and it's not because of the language.

The movie is good, depressingly good, beautiful photographed and the dance scenes are, as they say, great. Travolta is Tony Manero, 19, an Italian kid who has grown up in the tough Bay Ridge section of Brooklyn and is, as his inamorata tells him, nowhere going no place.

It is suffocating life from which Tony escapes on Saturday nights when he preens, every hair in place, body shirt open, and struts out of his rowhouse, into his hoody friends' car and makes it to the local disco. There Tony Manero is the undisputed dancing king: when he dances, everybody else clears the floor.

But the 2001 Odyssey Club in Bay Ridge is not the Plaza in Manhattan, and the people dancing there can't afford hotel rooms. In between the dancing, there are steamy scenes in back seats of cars. The sex here is crude, uncomfortable, methodical. Raunchy, is the way one mother described it. It occurs accompanied by four-letter words and without emotions, except perhaps in a final scene when a young woman has intercourse in the back seat of a car with several young men, and she collapses in tears as she realizes what is happening to her. The sex in the movie is unnervingly harsh, and one says that it is wrong.

A father who saw the movie says it has a "contemptuous attitude toward women. You simply don't deal with women the way they do in the movie." He says he would not let a 12-year-old see it. "If they're going to see something you don't want them to emulate, there ought to be some signal, something to guide them, to tell them what they ought to think about this. That's lacking in the movie."

While an adult viewer understand the message of the movie, a 12-year-old caught up in the music, the photography, the sensual rhythm of it may not. "There's too much tinsel to distract them," said the father.

Another father agreed, saying he would not let his 12-year-old see the movie because of "the language and the incidents - the subtleties of them aren't really apparent even if they understand the overt."

Dr. Michael Kerr. a psychiatrist at the Georgetown University Family Center, watched the movie without the soundtrack on a coast-to-coast flight while he worked, and says that "in general, the healthier the family, the better the child can handle things." The key, Kerr says, is not the event of seeing the movie but whether the child can absorb the experience and talk about it within his family.

This is good, professional theory, but Kerr didn't hear the words repeated - at first shockingly, then monotonously, always as meaninglessly as the sex.

The resident 12-year-old has wanted to see the movie. He has trotted out all the reasons: "All my friends have seen it. It's great." And the bludgeon: "I even know a 10-year-old who's seen it." So the movie was viewed recently in part to judge whether the 12-year-old could see it.

He was told the following morning that yes, it was a good movie, the photography was beautiful and the dancing was great, and that no, he couldn't see it. Not because of the language which is, indeed, vulgar. He's heard all the words, or at least most of them. But because of the way the movie treats sex. He was told that parents never know how much their children really know about sex, how much they understand accurately, and how many wild, acrobatically impossible misconceptions they've gotten from friends and siblings. And he was told that parents don't always know what their children think about sex, but that in this instance his parents did not want his attitudes further formed, or warped, by the harsh raunchy sex in "Saturday Night Fever."

It was time, he was told for a talk with his father.