This country's hottest new phenomenon in adolescent entertainment is strutting onstage in a black leather teddy, spike heels and a mask. Five thousand frantic fans, from awed 5-year-olds to their even more awestruck fathers, cry out proclamations of love to their Tiazinha, or Little Auntie. She flashes back a look that says Be prepared, slaves, because love hurts.

A perspiring 12-year-old boy in silk boxers, chosen from the crowd, is about to find out. First, a love tap with Tiazinha's leather switch. Whack! Ouch! Now she has cellophane in hand, ready to rip peach fuzz off her victim's baby fat with hot wax.

A young girl wearing a glittery Tiazinha head band and hugging a Teletubby is crying "I love you, I love you, Little Auntie!" A fifty-something man waves his copy of Tiazinha's 26-page spread in Brazilian Playboy, the biggest-selling magazine issue of all time here in the Western Hemisphere's second-largest country. It sold even better, in fact, than her popular Tiazinha Sticker Book, the one where Brazilian grammar school kids can collect all of her S&M outfits--whips and masks to boot.

"It felt great!" panted chubby 12-year-old Murillo Soares Maia, a faithful fan of Tiazinha's TV show for adolescents, unfazed but for a red blotch on his thigh after participating in this stop of her live tour. "I can die now. I've just been hot-waxed by the coolest person on Earth."

Or make that the hottest--at least in Brazil, the country where sexiness is next to godliness. Japan has its Pokemon; the United States has the Phantom Menace. But in Brazil, Tiazinha--really 20-year-old Suzana Alves, dancer and model turned television dominatrix--rules, quite literally, with an iron fist.

That a self-described dominatrix could become one of Brazil's biggest television stars for children, teenagers and adults alike is raising eyebrows here, even in the land of the dental-floss bikini. A few elected officials have called for tougher regulation of television programs.

Yet perhaps more interesting is the fact that the outcry has been relatively meek, and the applause louder. But this is not the first time in Brazil that a soft-porn actress has become the popular host of a children's television show. Tiazinha's whippings and waxings would never play in Peoria, but here in the Brazilian heartland the act is taken in stride.

"There seems to be a natural progression here from becoming famous for shaking your boom-boom to then getting your own children's show," said James Cavallaro, an analyst for Human Rights Watch in Rio de Janeiro.

"Models and sex symbols become the biggest stars among kids, and parents don't seem to care that their children are watching someone who just posed for Playboy," Cavallaro said. "There is a different view of the body here. Brazilians just don't have many taboos with sexuality."

Alves is living proof. She got her start only last year on a teenage quiz show where she used hot wax to punish adolescent boys who answered questions incorrectly. Then, quickly, her fame exploded beyond all demographic strictures, beyond all reason.

Her debut CD--made before she took even one singing lesson--has gone platinum in less than three months. Besides her own line of sexy lingerie for adult women, she now has her own brand of Tiazinha children's shoes and a Barbie-ish new doll. Notebooks with her sexy image are all the rage in Brazilian schools. She's being put on the cover of state lottery tickets. And the "Adventures of Tiazinha" will premiere this month on TV--a daily program in which she plays a superheroine with a whip and mask.

Her live performances of music and waxings (she lip-syncs her tunes, but no one seems to care) are luring sellout crowds. Her fame made the Tiazinha costume one of the five most popular during February's Carnival celebration, of which Alves was crowned queen in Rio de Janeiro.

"You had everyone from tiny children to middle-aged homosexuals cracking whips as Tiazinha," said Peter Fry, an anthropologist at the Federal University of Rio de Janeiro. "It was one of the stranger things, even for Carnival."

But Tiazinha's victims aren't the only ones crying. Her few vocal critics here say that she is an example of Brazilian children's overexposure to sexuality. "I think we have to understand when a good thing has gone too far," said congresswoman Martha Suplicy, an author of books on sex and adolescence who advocates stricter government controls of racy programs for young audiences. "We should celebrate our sensuality, but there have got to be limits, too."

She continued: "We have no studies that indicate these shows are promoting sex at younger ages or an increase in child sex abuse. But these are already big problems in Brazil, and you have to suspect that this is not helping."

Alves is merely the latest in a long line of Brazilian television stars who have blended eroticism and adolescence. Their fame is possible, experts say, because of the paradoxes in Brazilian society.

While theirs is the world's largest Roman Catholic country, few Brazilians find contradictions between their religion and their sensuality. Alves herself--the daughter of an evangelical Christian mother--carries a dogeared Bible with her at all times.

Carla Perez, a Playboy model who made famous a sensual dance move and claims to have "the best butt in Brazil," eventually became host of a popular teen talk show. But the pioneer in the field in the 1980s was Xuxa (pronounced SHOO-shah), or Maria da Graca Meneghel, today one of Brazil's wealthiest women. Though now a single mother who dresses somewhat more demurely, the blond former soft-porn star wore micro-minis and tiny tops on her top-rated children's program.

Now, Tiazinha has simply taken off the mini--and added the mask and whip.

Alves arrives for a lunch interview at a fashionable restaurant in Sao Paulo's Jardins neighborhood, the Brazilian Beverly Hills packed with palm trees, chic boutiques, film stars and the idle rich.

She dashes inside sporting the everyday street facsimile of her Tiazinha outfit, a low-cut black bodysuit with high heels, pearl choker and black Gucci shades. Gasps of recognition come from diners, who ask their waiters to get them autographs.

Alves, who began modeling in yogurt commercials at age 4, dismisses criticism that she is marketing sex to adolescents.

"I think children and teenagers both see through my mask," she says. "This is all an act--I'm really just a sweet, simple girl who is having a good time. I think my fans see it as silly, too, not just sexy. . . . We also underestimate the ability of children to recognize that I'm just a fictional character."

Alves, who has a girlish quality in conversation, says she's doing Brazilian womanhood a favor. She was first turned down for a role as a dancer on the same show in which she began appearing as Tiazinha. Why? They only hired blond girls.

"It's always been like that--most Brazilians are dark, but TV wants to hold up the blond woman as the image of the perfect beauty. I'm helping spread the message that girls don't have to be blond to be desirable."

Her popularity has become omnipresent here. On a flight to Belo Horizonte for a concert in Brazil's third-largest city, passengers went wild when she got on the plane. A woman from Seat 8C dashed up to ask for an autograph for her 4-year-old. "She can't stop singing your songs!" said Fatima Abril, 38.

Then a slightly drunk Dale Oliveira, 30, from 23B took off his shirt and gave it to Alves to sign. "Oh, sexy baby!" he said. "Sign it 'To Little Dale, the best lover in my life.' "

At Alves' concert later that night, a man brought his son, Jota Lennon, 5, to see Tiazinha perform. Little Jota is asked what he thinks of Little Auntie. "I like her butt!" he giggles.

His father is asked if he thinks Tiazinha is a good influence on a growing boy. "Look, you Americans are so damned repressed," he says. "What's your problem with sex, anyway? We're the healthy ones. You all just need to stop being so uptight."

CAPTION: "I think children and teenagers both see through my mask," says Suzana Alves.