While Sydney's once-thriving nightclub scene dies a slow and painful death, another type of venue is emerging from the shadows and taking its place - legal sex clubs. Once upon a time, these clubs were only mentioned in hushed tones and you had to know someone who knew someone. These days, they advertise in mainstream press, their owners appear on TV as sex and relationship experts and people are proudly "checking-in" to sex clubs on social media.

And in Sydney, they're booming. Four sex clubs have opened in the past four years - two in the Kings Cross and Darlinghurst area, one in St Peters and another, just two months ago, in the inner west suburb of Annandale.

Lawrence and Jess run Our Secret Spot, a sex club with premises in Darlinghurst and Annandale in Sydney. Credit:Christopher Pearce

In the era of hook-up phone apps, that might seem counter-intuitive. But venue owners credit two unlikely factors for the resurgence of sex clubs - the lockout laws, which are about to be lifted, and the overwhelming "yes" vote on same-sex marriage in late 2017.

"Our customers are looking for venues where they can let their inhibitions run wild without having to worry about licensing or the police or judgment," says Lawrence Jay, who owns Our Secret Spot in Darlinghurst and Annandale with his partner Jess Cattelly.