Sex party host lifts the lid on ‘world’s most secretive’ X-rated club loved by celebs

With beautiful attendees decked out in black-tie, free-flowing champagne and a DJ spinning tunes, at first glance, it looks like any other A-list party. Until, that is, a group moves to the balcony for a frenzied orgy overlooking New York’s iconic skyline.

Welcome to Top Floor – a playground for guests to live out their wildest fantasies. Here, former host Marz Katz lifts the list on one of the Big Apple’s most elite, secretive, and lascivious sex parties – from BDSM cages to nervous celebs, and the secrets to getting your name on the guest list.

Launching back in 2011, Top Floor was initially a secret after-party in New York, with no website or social media presence and only word-of-mouth to invite people.

After an initial burst of success, it closed for six years before a re-launch led by Katz in 2022, with a new membership structure of £520 a year, a strict vetting process and a black-tie uniform.

They even launched a WhatsApp group, which helped transform it from a secret party to a thriving community of more than 800 sex-mad New Yorkers.

Today, they host wild sex parties for up to 190 people, and romps on the balcony – offering a truly unique way to see the world-famous city skyline – are commonplace.

Katz said: “One balcony is rated PG. The other, without neighbours, is X-rated, so people get away with quite a bit.”

BDSM cages are popular, and “beautiful group sex” often ends in applause, and she also says she’ll never forget the time one person proposed a mid-sex party.

“It was really cute,” she says. “Top Floor also had an on-site conception. Those twins are lovely boys now.”

The venue recently launched a BDSM night along with Bi-Sensual – a new night that focuses on bisexuality. There’s also “Marked” events, which explore “dominance, devotion and discovery”.

Katz, who left last year to start her own sex party series, said: “It’s always black tie, fancy schmancy.

“BDSM versus play is not as sex-oriented. Sex happens, but not as much of it. There are more tools and implements. I remember a cage with two women in it.

“I also remember a dominatrix punishing people for their confessions.”

Suprise celeb haunt

And even the rich and famous have attended, but she remained tight-lipped about exactly which celebs like to visit Top Floor.

She says: “They get nervous, but we do the best we can to reassure them.

“To my knowledge, there have not been any leaks.”

Katz, who is in polyamorous relationships herself, said nothing is scheduled apart from a DJ set and food – leading to “completely authentic” action in the bedroom.

She adds: “I remember some beautiful group sex in the main bedroom with a very respectful audience and applause afterwards.

“The philosophy is that nothing is performative. 

Evolving from an after-party to a community is Katz’s favourite thing about hosting a sex club.

“When you find like-minded people, where the connection is that we’re all sex-positive and predominantly ethically non-monogamous… people from completely different stratospheres of society connect in the most beautiful way,” she says.

While sex parties were once mainly the stuff of urban legend, these days there is no shortage of choice.

“The New York play party market is oversaturated,” she says.

“People can go to a different party every night starting Thursday. The competition is crazy. The range of experience is highly variable.”

High attention to the vetting process is super important. I have a big emphasis on safety and taking care of peopleMarz Katz

One major competitor is SNCTM. After starting out as a seedy nightclub, it now hosts parties in New York, Los Angeles, and Miami, where the rich and famous cough up the £9,300 entry fee to explore their most intimate desires in complete anonymity.

The club’s masquerade parties became a huge hit in Hollywood society – attracting stars including Steven Tyler, Bill Maher, and even Gwyneth Paltrow, who is said to have attended with her then-boyfriend, producer Brad Falchuk.

Meanwhile across the pond in the UK, guests flock to private members’ clubs including Feast of Temptation in the heart of London’s Mayfair.

Now, Katz is launching her own sex-positive brand – Effervescenz – next week after leaving Top Floor in 2025. She will be throwing her first party on February 13 and, as with Top Floor, has a strict vetting process that includes STI testing.

“Having been around long enough, especially with Top Floor, where I did all the community management and vetting, I interviewed every person for at least half an hour on Zoom,” she said.

“High attention to the vetting process is super important. I have a big emphasis on safety and taking care of people.

“Different parties have different ways of vetting. The ones that grow quicker tend to have lower barriers to entry.”

From November 2023 to June last year, Katz rejected 38.8 per cent of applicants to Top Floor in the first round – and of the 61.2 per cent that got through, 7.3 per cent of those were then rejected.

Strict conditions

Once they’re through to the final stage, guests must sign a document with conditions.

This includes privacy, not giving away someone’s ID, and phones kept out of sight in shared spaces.

Photos are allowed – but only before or after the party, or in bathrooms.

Her “green flags” in wanna-be guests are experience in the sex party scene, and a curiosity “about tantra and kink”.

Her “red flags”, on the other hand, include poor grammar, extreme views, and couples where only one of them seems to be doing the talking.

She once turned down a couple because they began arguing during the interview in front of her.

She added: “We never discriminate against single men. Pricing is even across the board. No gender-tiered pricing at Top Floor or Effervescence.

“There’s an online application. It gets reviewed with photos, social profiles and answered questions. If it doesn’t pass the first round, there’s no response.

“If they pass, they get invited to a personal Zoom. Prior to the Zoom, applicants read a rules and regulations document and find a hidden word to prove they read it. Then they do a half-hour-plus Zoom. Couples do it together.

“After that, they receive either an acceptance or a polite rejection email. STI tests are mandatory prior to attending an event.”

Despite the rigorous nature of the vetting process, Katz describes the interviews with potential guests as “beautiful experiences”.

“What I’ve learned is there’s a big contingency of people who like the opportunity [to go to a sex party],” she says.

“But they’re really looking for connection.”

Sex party host lifts the lid on ‘world’s most secretive’ X-rated club loved by celebs