And what happens is anything from straight out bonding to burlesque dancing, body shots and bondage, says Skirt Club co-director Renee Nyx.
Nyx is based in London but grew up in Sydney, and joined Skirt Club UK in late 2013 - attending the first Skirt Club founder Geneviève LeJeune held.
LeJeune had attended "play parties" with her male partner, (now her ex) but felt she was doing things for his pleasure, not her own, and wanted a place of her own to experiment.
Nyx, who is bisexual, went along to see what the fuss was about.
Turns out she wasn't the only one. Skirt Club now boasts a membership of about 5000, most of them in the UK, and in Sydney already has 50 members, largely through word of mouth.
Nyx says there is a demand for the club in Sydney - on a visit home last year it took only a few says and a series of swipes on dating app Tinder to find 35 women interested in the concept.
"There is truly not a place in Sydney at the moment that bi-curious and bisexual girls feel necessarily welcomed," Nyx says.
"There is a very strong gay scene, and that is fantastic but there is a bit of intercommunity negativity towards this.
"Some bi-curious girls may not feel comfortable enough to go to a lesbian gathering. They might not be comfortable enough to date a gay girl, because they are thinking 'you know what, I'm here to experiment, I don't know what to do, I'm nervous', so this an opportunity for women to explore in a safe environment and feel empowered."
LeJeune was stunned by the popularity of the club when she set it up.
"Female bisexuality is nothing new, it has been common for centuries just never openly discussed," she says.
"By spearheading a movement that gives women the freedom to choose, we have opened the door to public discussion. And it turns out women's appreciation for one another is widely favourable."
Skirt Club runs two levels of events - Mini Skirt - a "try it on for size" post-work social event, usually in a bar, where newbies basically meet other women, and see what the concept is about.
Mini Skirt events are held every three or four weeks.
"There are no expectations at all - some women will honestly just go meet other women, they'll connect and swap numbers perhaps for a date or a one-to-one catch-up or they might just go on their way," says Nyx.
Others might be intrigued enough to try out the more risque side of Skirt Club: play parties, held about every six weeks, usually at private homes, which feature themed nights, guest speakers, 'and of course, play', Nyx says.
Again, says Nyx, there are no expectations.
But, she confesses, sexy entertainment like burlesque dancers, guest speakers (recently one party heard from a dominatrix), candles, music, fragrances, hostesses ensuring people are introduced to each other and are comfortable, cocktails and games like body shots set the scene: "It's not just a sex club, but let's say sex will happen ... somewhere, if that's what a member wants."
"We do feel in many ways that this is quite empowering," says Nyx.
"True independence comes from owning your sexuality - and feeling free to explore it.
For first-timers the experience can be intimidating. Newbies are given a vintage key charm, tied around the wrist with a black ribbon, both as a keepsake and as a subtle way of telling others they're new to the game.
"What we offer is an environment in which to do that which is safe and non-threatening," Nyx says.
"And it can be a scary thing to take that leap."
Most Skirt Club members use pseudonyms to protect their privacy (Nyx is among them). Some have male partners, some are bisexual, some 'just don't know, and that's why they're here'.
"Some women are just trying it out. Some do it to say that they've lived a fantasy. Everyone is different," Nyx says.
"It's not that they want to identify as anything particularly, they are just thinking 'I just want to see if this works for me', Nyx says.
Skirt Club Sydney's launch is a mini Skirt event is on June 29. To attend, you'll need to apply - and survive the vetting process to be accepted as a member.
Details at the Skirt Club website.
