LAUSANNE —It's almost spring, and last week Lausanne was already taking its panties off.

The Arsenic, an art center in the Swiss city, displayed an interactive performance about sex workers and screened films such as A Blowjob Is Always a Great Last-Minute Gift Idea. The Galerie Humus unearthed a little known collection of erotic pictures and objects. At the City-Club, viewers could watch other "ballsy" movies. There was sexy dancing at the Bourg, while the Romandie rock club celebrated the clitoris.

What a week the Fête du Slip (literally "Festival of Panties," also meaning "big mess" in French) has been!

Since 2013, the festival conceived by a pair of brother and sister intellectuals, Stéphane and Viviane Morey, has been raising the temperature in Lausanne. If Stéphane were a J.R.R. Tolkien character, with his diminutive size, thick beard and glasses, he would belong to the Dwarves family. Viviane, svelte and blonde, wearing a discreet piercing and a gingko leaf for a necklace, would be an Elf — she is loquacious in her reflections and laughs heartily.

The son of Earth and the daughter of Air don't look physically alike, but they finish each other's sentences. He's 28, she's 33, and she enjoys poking fun at her brother, who is used to Viviane's displays of tough love.

"We really got along when we starting doing the Fête du Slip, even though we asked ourselves if we'd be able to work together professionally," Stéphane explains. "It's quite nice knowing that even if we argue, if we're at each other's throats, he'll always love me," Viviane adds.

But how do you end up creating such a hedonistic, such a Babylonian project in Lausanne? Stéphane is mostly interested in cinema, and Viviane prefers literature and music, but both have degrees in social sciences. Viviane undertook gender studies. Stéphane listened to his older sister talk about the social construction of the male and female gender before following into her footsteps. He completed a Master's degree in visual anthropology in Berlin, where he discovered the "positive sex" and "alternative porn" cultures.

"Sexuality is a fundamental structure of one's identity and personal construction," Viviane says. "The U.S. produce about 10,000 porn films per year! This means it needs to be thought about and talked about. Whether we like it or not, pornography is part of our culture."

Stéphane believes "everyone consumes porn," even if it's just through advertisements. "It's also a way to conceive social relations between genders," he says. "We're sick of prudishness. Sex education classes never talk about pornography on the pretext that it's dangerous for young people. But do they all end up in a psychiatric hospital?"

No hue, no cry

The Internet, same-sex marriage, the highly publicized chronic mischief of Dominique Strauss-Kahn, the former chief of the IMF. Sex is everywhere. A multidisciplinary festival centered on sexual issues, the Fête de Slip neither advocates nor condemns sex. It simply explores and questions it.

In not-so-ancient times, events such as this one would have led to a major outcry. Times are changing. "We're almost disappointed," Viviane says before Stéphane adds, "It's surprising. We were expecting virulent protests."

But there was no such reaction, just a few invectives in the letters to the editor of 24 heures, inaccurately denouncing a misappropriation of public funds when the Fête du Slip is actually financed through crowdfunding and, this year, with a grant by the region's lottery. Even certain feminist groups from which they could have expected an angry reaction answered positively. The religious, meanwhile, seemed blissfully unaware — and may they remain unspoiled.

Lausane's cultural institutions opened their doors with an "incredible generosity," the founders say. Are the world's panties on fire? "It's hard to answer that," Viviane says.

"Traditions have become more flexible. The Internet generalized porn. It's easier to talk about it." adds Stéphane. "A space of openness and freedom was created at the same time as a space for reactionary attitudes and conservatism. We saw that with the demonstrations for same-sex marriage."

And where does Fifty Shades of Greystand in this globalized rut? The Morey siblings have neither read the book nor seen the film. Stéphane knows enough to say that the flagship of "mommy porn" isn't really representative of the BDSM world the way the Fête du Slip shows it. The crude film Love Hard, Viviane adds, is "very poetic" and "shows the beauty, the trust, the tenderness, the consenting nature of the people in a BDSM relationship."

She's too much of a belletristic literature connoisseur to devote time to clumsily written books, and prefers reading Story of Oagain. She does, however, concede that the Fifty Shades bestseller may have the merit of making erotic literature mainstream.

Do their parents know what these two are up to? "Of course," says Viviane. "We talk with them a lot. My dear mother often asks why sex is so important."

Says Stéphane, "We maintain the dialogue, even if we don't agree on certain points. Our mother instilled this principle in us: "Don't curse the darkness, light a candle!" That's what the Fête du Slip is about. We prefer celebrating progress rather than complaining and simply denouncing injustices without offering alternatives."

Born in an evangelical family, Viviane and Stéphane grew up in western Africa. "We were raised in an atmosphere of openness, of recognition of differences and otherness," Viviane says. "We've been called "missionaries of positive sex." This makes us smile because there's some truth in it."