Learn to strip!
Split up in pairs, the young women take turns sitting on each other's laps and swaying their bodies back and forth. It's not long before the whole class explodes with laughter.
"I'm getting hot!" one girl exclaims, setting off another round of hysterics.
It's not a common scene among Thai women, who are usually quite shy about sex, but this tutorial in striptease is strictly for fun.
There are international students in the class, and high-ranking corporate women, a couple of designers, and even one who works for the United Nations.
"I'm sure everybody's done it before - dancing sexily in front of the bedroom mirror wearing next to nothing," says the instructor, Busakorn Vorameth, who owns the Rum Puree Dance Studio located on the fifth floor of Bangkok's Amarin Plaza.
Striptease may be the realm of saucy nightclub entertainers, Busakorn says, but all of her students are "good girls" and career women, ages 18 to 45.
She's no slouch herself. A Harvard University grad in design management, Busakorn works in computer-aided facilities management for a New York consulting firm.
So what's she doing teaching other women how to peel off their clothes?
While she was studying, Busakorn wanted a healthy hobby that didn't involve just going to the gym.
She took several dancing classes in New York, among them salsa, belly dancing - and striptease.
There, her friends were learning striptease so they could give their boyfriends a thrill. What about Thai women?
Busakorn hasn't actually asked her local students why they're taking the class, but she suspects it helps them "step outside the boundaries".
"A lot of Thai girls feel they're too restricted. They have to be polite and they're always told to do this and that. This class may be 'taboo' for some, but when they come here they're able to freely express themselves."
Striptease certainly has its bawdy connotations, but Busakorn explains that there's a world of difference between the Rum Puree studio and Patpong. She sees the class as artistic, not sexual.
"The dancers you see in places like Patpong wiggle their bodies a bit, but they look dead," she says. "They've never been taught to dance."
She is, however, plotting a bit of a coup. She's thinking of pushing the boundaries a little further and taking her students into Q Bar to perform a striptease for the patrons.
They'll stay dressed - roomy T-shirts coming off to reveal not-so-roomy tees - but isn't Busakorn worried about crossing the line by taking the girls public?
"We'll have to communicate with the audience and make sure they know this is not about sex," she says.
Meanwhile - and just for fun, mind you - the class consists of pole dancing and "erotic dancing".
No skin is bared. Beginner moves include caressing your hair, tracing the outline of your body with your hands and stroking your arms.
They have a go at lap dancing, sitting on another girl's lap with legs spread and briefly caressing her thighs.
A few jokes prove essential in thawing the awkwardness. "Can we try it on a guy now?" one girl cracks.
Another wonders in mock concern, "What if the guy doesn't have any money?"
The students are wary of people finding out about their "higher education" at the cost of their reputations, but for the most part, they're enjoying themselves.
Busakorn stresses that striptease, like any other form of dancing, is an art, and it can both help you explore your sexuality and boost your confidence.
"It's something different," says Lily Ti, a half-Thai, half-Malaysian international student. "At first it was awkward, but after we got to know each other it was fun!"
"It doesn't get me high or anything - it's just fun," concurs a freelance writer who asked not to be identified.
There's no unhealthy obsession here. Most of her students have previously taken classes in belly dancing, jazz or hip-hop.
"When I heard about the striptease class I thought it would be fun to learn something new. It's a real laugh!" says jewellery designer Angkhanang Martino.
"Fun" is clearly the operative word.
"You've got a body, why not use it?" adds Pornswan, who's the president of her own company. "Are you going to just let it lie there and do nothing?"