With all due respect to Salt-N-Pepa, let's talk about Todd. Todd (not his real name) is a friend of a friend. He's a rare breed--a finance guy who lives in L.A. He's been dating the same ladylike woman for three years. They are the picture of late-twentysomething, Amstel Light--drinking America. The very first time they slept together, they had anal sex. Miss Ladylike had never tried it before. For the next five months, anal was the only kind of sex they had. Supposedly, Todd had intimacy issues, and penetrating Miss Ladylike's rectum was less emotionally intense than venturing into the vagina. Eventually, Todd did the deed with Miss Ladylike in the usual way, and continues to, but they still have a whole lot of anal sex.

So, apparently, do a lot of other people. The Centers for Disease Control and Prevention estimated that in 2002, 38 percent of men ages 18 to 59 had entered a woman's back door. Thirty-five percent of women ages 25 to 44 had invited men in. Ten years before, only 26 percent of men and 20 percent of women reported having had anal sex.

"Anal is the new oral," says syndicated sex columnist Dan Savage. "I used to get letters from women about giving head. Those letters are now dwarfed by letters from women asking how to take it up the butt." Okay. But pronouncements and statistics that indicate the rising popularity of rearguard action don't address some nagging questions--the biggest one being how, presuming they haven't had their own rectums messed with, can so many guys justify asking women to let them take the service elevator?

Phillip, an engineer in Chicago, says he and his friends request a ride in the back seat because it's a harder-to-reach goal than old-fashioned intercourse. "Once a guy has anal sex, he's put on a pedestal by his peers," he says. He claims he hasn't had much trouble getting women to agree to it. "I only had to persuade two girls. [I asked] 'Can I put it in your butt?' At first they were like, 'No, it will hurt.' Then time after time of having sex with them they finally said okay. It hurt them the first time, but after that they always said they enjoyed it--if not a little, then a lot."

For other men, the appeal of anal penetration is less the novelty--and the fact that it gives them a good story to tell over beers--and more the psychology. "For most of my friends, it's sort of a domination thing," says John (not his real name), 30, a writer in New York. "[It's] basically getting someone in a position where they're most vulnerable. My friends enjoy that and they tell their friends they did it. But it's not like girls are ready for it--it's something they do when they're really drunk."

"There's an erotic undercurrent about being in control of a situation," says Edward Ratush, a psychiatrist and sex therapist in New York. "It's a very ego-focused thing for the guy."

Albert (his middle name), a good-looking 29-year-old who's fairly well-known in the music industry, says he asks the women he dates to have anal sex with him because it raises the level of intimacy in the relationship. He doesn't demand anal sex--especially not if it's a one-time hookup--but he won't commit to a woman who refuses to grant him a backstage pass. "I had a girlfriend who I was with for a long time and she wasn't into it," Albert says. "There was definitely a thing in the back of my head like, 'I can't marry her.' How can I, knowing I can't go to all the places I can go with her? The physicality of it, being painful or whatever, shows how comfortable the girl is with you." Here, he pointedly stops short of romanticizing screwing a woman rectally. "Ideally, every girl is a disgusting pig who wants it," he says. "But only with you."

There's evidence that some women do like anal sex, and that they're as into having it as some men. The dating website Lavalife recently polled 20,083 members in its "Intimates" section. Thirty-five percent of female respondents claimed to enjoy anal sex. "It's a myth that every straight man wants it and the women who give it up do just that," says Tristan Taormino, author of The Ultimate Guide to Anal Sex for Women.

Dawn (her middle name), a 34-year-old married woman who lives in Ohio, first tried anal sex at her husband's suggestion, only to discover that she was much more into it than he was. "It's better," she says. She'd like to have it more often, but it's currently off the table. "He's got more hang-ups about it than I do," Dawn says.

After the forbidden territory has been conquered, some men find they have psychological issues with the act. Even Albert, the one who won't tie the knot without a key to the back door, admits that. "You're thinking, 'I don't want to hurt her, and I don't want shit to squirt out at me,'" he says.

So if you can't be certain whether the woman's enjoying herself or just submitting to peer pressure, and the act itself can be unpleasant, what's the motivation for demanding it? For Todd, so his friend says, it was about maintaining emotional distance. Albert says it's about enhancing the intimacy between two people. But the more plausible explanation is that it's about accessibility--and instant gratification. Now that anal sex has been propelled higher on the mainstream menu by a hypersexualized culture and the proliferation of porn (see Ass-Hole O Mio and the Anal Excursions series), some men can't help but order it. And some women feel the need to offer it.

A few years ago, Albert says, he was hosting a party at a New York nightclub. A girl in attendance began hitting on him aggressively, and after the party they headed uptown to her Columbia dorm. "I'll never forget it," he says. "She went down on me immediately, in the kitchen, then came up and said, 'I want you to fuck me in the ass.' That's some porno shit that most guys dream about." And when he told his friends about it later, he brought down the house.