One day in my junior high school, all the girls were called to the auditorium to see a film. It featured, as I recall, rosebuds floating on a pastel screen. It was a standard sex-education film, and it left us completely mystified.

As it turns out, we were the lucky ones. Though we didn’t understand what people did during sex exactly, we were confident that sex would not be boring. Since we lived in the halcyon, pre-revolutionary era, this was a hot topic. I can’t imagine that teens today whisper much about who’s doing what or how they do it. All they have to do to get the answers is read the latest foray into the more-than-you-want-to-know genre of “human sexuality” studies: the exhaustive, 56-page, chart-laden, jargon-ridden, federally financed “Sexual Behavior and Selected Health Measures: Men and Women 15-44 Years of Age, United States, 2002.”

The “news” when the study was released recently by the U.S. Centers for Disease Control and Prevention was that teenagers are engaging in a lot of oral sex — 12 percent of boys and 10 percent of girls ages 15 to 19. (Feminists cheered triumphantly the fact that these numbers were so similar — that girls seemed to be on the receiving end as often as the giving one.) There was some concern among “experts” that this behavior had become so widespread because teens thought it was a good way to avoid sexually transmitted diseases.

But maybe there’s a more obvious explanation. Teens have been exposed to so many lectures, books and classes (based on studies like this one) that they’re bored by the very idea (yuck) of intercourse. Every potential high-school loose leg must find the prospect of getting to third base tedious nowadays. Oral sex, considered in this light, may be just an inventive way to stave off the — yawn — inevitable. A few more studies of this ilk and our national birth rate will plummet even more precipitously than it has already.

But there is good news — sort of. The percentage of respondents having only oral sex drops to 3 percent by the time they are age 22 to 24 — presumably because most have by then mustered the courage to do the dastardly. No doubt some of these world-weary youths reluctantly undertake oral sex only because they fear that they will one day be required to participate in a survey, and they don’t want to be embarrassed.

Indeed, one simply can’t help wondering just how representative of the population at large were the 12,571 souls who voluntarily agreed to answer intimate questions about their sex lives. What kind of weirdo does this? The study does pointedly apologize for the underreporting of one group — the homeless — helpfully explaining that this failure derives from the fact that they don’t have homes in which to be interviewed. Yes, the interviews are conducted at the subject’s house. Does one serve coffee or tea to someone who is asking how many sexual partners you’ve had? I might have demanded more than the $40 “token of appreciation” that respondents received.

Minors who participated were required to get approval from a parent or guardian. (Hey, Mom, I’m going to discuss oral sex with a stranger, but first I need you to sign this permission slip.)

All the interviews were conducted by one of the more than 200 women (why no guys?) hired and trained by the University of Michigan’s Institute for Social Science. But would all the training in the world allow one to keep a straight face during these conversations? “Thinking about the last 12 months,” one question begins soothingly, “that is, since [month/year], how many male sexual partners have you had? Please count every male sexual partner, even those you had sex with only once.” (And do you think I could have another cup of coffee, please?) For those unused to terms like “sexual intercourse,” the interviewer explains that “sometimes this is called making love, having sex, or going all the way.” Well, now you know…

The interviews with the male subjects — which included questions not only on the number of partners, their gender and the orifices involved — ended with quite a finale: “Have you ever spent time in a jail, prison or juvenile detention center?” I don’t know about you, but that would have been my first question.

There were several politically incorrect findings: e.g., African-American males are the most promiscuous (34 percent said that they had had 15 or more partners in the past year, compared with 22 percent of white male respondents and 18 percent of male Hispanics). As for homosexuals — there aren’t as many as you thought.

About 6 percent of the male subjects reported engaging in sexual activity with other men, while the women were more adventurous — 11 percent having done so with other women. Of the women, though, only 1.3 percent restricted themselves to female partners in the past year. (The authors of the survey do not offer an explanation for this last point, but one can’t help thinking it may be the result of the LUG — lesbian until graduation — phenomenon, in which a little experimentation is considered de rigueur.)

Most lesbians, by the way, aren’t married, according to the survey. Fancy that. We needed a government study to learn that only 0.8 percent of lesbians are married? (I’m assuming that married refers to marriage to a member of the opposite sex.) And if you’re a lesbian, don’t go looking for love in the countryside — only about 0.8 percent of lesbians are rural lesbians. And we need to know this because?

Some may wonder: How does education affect sexual behavior? Mothers with more years of schooling are more likely to have daughters who engage in oral sex. I suppose women must now ask themselves: If I decide to go on for graduate work, will my daughter provide unspeakable pleasures for all the boys in her eighth-grade homeroom? Conversely, higher levels of education put a damper on your own sexual activity. It is noteworthy that 7.2 percent of women with bachelor’s degrees had had no sex in the past 12 months, compared with 5.8 percent of those who had a high-school diploma or less. The big losers, oddly enough, were women with only some years of college — 8.2 percent. Nobody likes a quitter.

Perhaps the educated classes have read so many sex studies that they are less likely to want the real thing. Here is today’s most inescapable fact of life: We know too much about sex. There is no mystery, no romance and no sense of naughtiness. (What’s the fun in sleeping with another woman’s husband if there’s no frisson of guilt?) Sex studies just aren’t very sexy.

Southern women used to have the right idea about sex instruction: When my older sister was getting ready to walk down the aisle, my mother wafted into the room and liltingly asked: “Is there anything you’d like to know — or maybe you’d rather have a Virginia ham sandwich?” My sister wisely opted for the ham sandwich and has been happily married to the same man for several decades.