A new national sex survey is out. Published in the Journal of Sexual Medicine, it reveals who’s doing what, with whom, and how. It clarifies the prevalence of gay sex, teenage intercourse, and oral gratification. But the big story is the increase in anal sex reported by women—and its possible connection to female orgasms.

Let’s start with the foreplay: a few other trends worth noting.

1. What teens are doing. By ages 14-15, 10 percent of boys say they’ve had vaginal sex. By ages 16-17, the number is up to 30 percent. By ages 18-19, it’s above 60 percent. For girls, the trajectory is almost identical. Oral sex follows a similar trend. At ages 14-15, 9 percent of boys say they’ve performed cunnilingus. By ages 16-17, 20 percent say they’ve done it, and by ages 18-19, 61 percent say they’ve done it. Among girls aged 14-15, the number who say they’ve given a boy oral sex is 13 percent. By ages 16-17, it’s 29 percent. By ages 18-19, it’s 61 percent. If you’re turning 20 and you haven’t gone down on somebody, you’re in the minority.

2. Oral ubiquity. It’s funny to look back at the previous national survey, taken in 1992. In that report, the authors marveled at the mainstreaming of oral sex. Now the whole question of its normality seems silly. By ages 25-29, eight of every nine women have performed fellatio, and half have done it in the past month. For men and cunnilingus, the numbers are only slightly lower. More people think the president is a Muslim than adhere to oral chastity.

3. Reciprocity. Women are getting as good as they’re giving. By ages 25-29, 88 percent say they’ve received oral sex from a man, and 72 percent say they’ve received it in the last year. (Men confirm this: 86 percent say they’ve given it, 74 percent in the last year.) That’s pretty close to the 91 percent of men aged 25-29 who say they’ve received oral sex from a woman and the 77 percent who say they’ve received it in the past year.

4. Homosexuality. Apparently, a lot of people try gay sex, but only about half stick with it. By ages 18-19, 10 percent of men say they’ve performed fellatio. That number drops among men in their 20s and 30s. But among men in their 40s and 50s, 13 percent say they’ve done it, and 14 percent to 15 percent say they’ve received it from another man. Meanwhile, 11 percent of men aged 20-24 say they’ve received anal sex. For unknown reasons, that number declines in the next higher age bracket but then steadily rises in succeeding brackets, leveling off at 9 percent among men in their 40s and 50s.

Remember, these are “have you ever” questions. When men aged 20-59 are asked whether they’ve performed fellatio in the past year, the number is more like 6 percent. And only 4 percent say they’ve received anal sex in that time. But that’s a big jump from 1992, when only 2 percent of men admitted to sex with a man in the preceding year.

For women, the gap between trying gay sex and sticking with it is greater. From ages 20 to 49, the number who say they’ve performed cunnilingus ranges from 10 percent to 14 percent, but the number who say they’ve done it in the last year is more like a quarter of that.

5. Anal sex. Here’s the big story. In 1992, 16 percent of women aged 18-24 said they’d tried anal sex. Now 20 percent of women aged 18-19 say they’ve done it, and by ages 20-24, the number is 40 percent. In 1992, the highest percentage of women in any age group who admitted to anal sex was 33. In 2002, it was 35. Now it’s 46.

The last time I looked at the anal sex data, I figured that most women who reported having done it meant they’d tried it just once. I was wrong. If you push these women beyond the “have you ever” question, the numbers stay surprisingly high, and they’re getting higher. In 1992, the percentage of women in their 20s and 30s who said they’d had anal sex in the past year was around 10 percent. Now that number has doubled to more than 20 percent, and one-third of these women say they’ve done it in the last month. Among all women surveyed, the number who reported anal sex in their most recent sexual encounter was 3 percent to 4 percent.

That’s a lot of butt sex. And remember, this is what women are reporting. If anything, they’re probably understating the truth.

So what’s with all the buggery? Is it brutality? Coercion? A porn-inspired male fantasy at women’s expense?

Apparently not. Check out the orgasm data. Among women who had vaginal sex in their last encounter, the percentage who said they reached orgasm was 65. Among those who received oral sex, it was 81. But among those who had anal sex, it was 94. Anal sex outscored cunnilingus.

No way, you say.

Way. Read the data. Table 5, Pages 357-8.

What could explain this? Taboo thrill? Clitoral migration? Some new kind of vegetable oil?

Here’s my guess. Look carefully at Table 4, Pages 355-6. Only 6 percent of women who had anal sex in their last encounter did so in isolation. Eighty-six percent also had vaginal sex. Seventy-two percent also received oral sex. Thirty-one percent also had partnered masturbation. And the more sex acts a woman engaged in during the encounter, the more likely she was to report orgasm. These other activities are what gave the women their orgasms. The anal sex just came along for the ride.

So why did the inclusion of anal sex bump the orgasm figure up to 94 percent? It didn’t. The causality runs the other way. Women who were getting what they wanted were more likely to indulge their partners’ wishes. It wasn’t the anal sex that caused the orgasms. It was the orgasms that caused the anal sex.

If anal sex is a trailing indicator of women’s sexual satisfaction, then by all means, let’s toast the new findings. Here’s to you, ladies. Bottoms up.

(For other ways to explain the orgasm data, see “ The Riddle of the Sphincter.”)

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