Nothing, as the sounds from the first club distracts her

She was no blushing virgin (though some said she did blush like one), and she'd accidentally ended up both watching and hearing more than she'd want to when out on her patrols. But she'd never seen anything like this.
The more she looked around the more she saw, in addition to all the ones having sex in the bathroom stalls, there were two women giving blowjobs through holes in the bathroom wall, at least two couples who had gone from grinding to actually fucking on the dance floor, women and men under the tables with their heads in their seated partners laps. A bit of extra x-ray vision showed that some of the less obscene looking couples that were just sitting on their boyfriends laps were doing it too.

She had to wonder what the club put in their drinks, or if it was in gas form, as she couldn't help but feeling more than a little hot under her collar, flying up there and watching.

'Huh, that's strange' Trying to follow the pipes from the bar came to an abrupt end, as it seems that part of the basement was led-lined or otherwise impenetrable to her sight.
Her hearing however, was another matter, there were squelching and other wet sounds, lots of heavy breathing and the occasional sound of viscous liquid running through pipes but not a single word was said. Under it all though, was the quiet hum of machinery.

While contemplating the merits of some super-speed and slightly broken windows and doors, she suddenly sees a large group of men and women arrive at the club dressed as heroes and villains. If several of the blondes weren't dressed like her, she might have wondered if the Justice League was having a party there.
Flying around to the front, Kara listens in on a guy dressed as Superman with his arms around a Supergirl and Harley Quinn talking to the bouncer, or rather talking at the bouncer at a mile a minute "...modelling agency launch party, and the club that nitwit of an assistant booked was as dead as a canary in a coal mine fire and you know, everyone says this is the place to go for some fun, and we all want fun, who doesn't like fun? Don't answer that, my assistant apparently doesn't like fun, but we love fun, especially the girls here, and me, so yeah, just wave everyone hot and in a super-suit through and that would be great, ok?"

The bouncer grabs the wad of bills the Superman waves around "Sure"

"Yeah, that's what I'm talking about, or with, money that is, money talks, and ..."
"Can we go in now Rex, it's cold out here in this flimsy thing and the guy said yes" the Harley says, before deciding that there's no reason to wait and just walks in, quickly followed by around 50 more people in assorted hero garb.

Deciding not to look a gift-asshole in the mouth, Kara quickly lands in dark alley next to the club, and then hurries over and mixes in with the models.

One of the other Supergirls looks over at her as they enter the club "God, what sort of try-hard are you? Why the hell would you buy something that thick and unflattering, we're supposed to have sexy costumes!"
Kara looks down at her suit and fluffs the skirt out a bit, scuffing the floor "Um, well, I like it"
"Nerd, but I guess the leather boots are pretty nice, too low heels though!"

Smiling and nodding, Kara heads off towards the bar.

A few minutes later, Alex Danvers receives a text

Agent Vasquez: "The dodo has landed, and entered Blaze's"
"Roger that, do you have eyes on her inside?" :Agent Danvers
Agent Vasquez: "No, the bouncer just waved us to the back of the line, apparently only people in spandex can jump to the front"
"What?" :Agent Danvers