Locking Kara up in a chastity belt

Following Roulette through a small side door, the room they enter is rather small and brightly lit with shelves and tables full of assorted unidentifiable metal pieces, as well as some very identifiable restraints.
Heading over to a short olive skinned woman dressed in tight fitting white leather and, incongruously, black combat boots Roulette asks "Are they ready?"

The woman finishes lining up the items on the table and nods "Yes, the whole prototype set is here, after all the success with the copies I don't understand why-"
Reaching out and taking her hand Roulette Interrupts her "And while your work has always been excellent, in this case I'm going to act as the owner of this place and your boss and ask you to leave. The prototype is mine to do with as I want, as is my new favorite here, and I'd like to prepare her myself" gesturing towards the disguised Supergirl.

Shrugging her shoulders and heading towards the door they entered through the woman looks Kara up and down "Hmm, firm and rather fetching, if you like them flat" before continuing on her way out of the room.

Looking down at herself while trying and failing to keep the hurt out of her voice, Supergirl complains "Why does everyone keep calling me flat! I'm perfectly normal..."

Roulette studies Supergirl for a moment "Hah! I don't think you're normal in any respect, though in this case she's right, you're definitively below the norm as opposed to your otherwise super aspects, who knows though, there are many both boring and fun ways to deal with that problem. "
Making a dismissive wave towards her, Roulette says "But that's for another time, right now you need to get rid of your thong, don't worry though, you don't have to flash me, keep the dress on if you prefer."

'If I prefer! Pfft, as if I want to show her my super-body... below the norm my ass...'
Grumbling a bit silently, she reaches up under her dress and the thong with it's house of El symbol falls to the floor "There, you've made me drop my panties, thong, whatever... congratulations"

Lifting up a pair of what looks like metal panties and holding them out towards Supergirl, Roulette adopts her Dominatrix voice and orders "Put on this pet."

Arresting her hands before they quite reach what Roulette is holding and squinting at the contraption Kara splutters "What... that... are those lead? What sort of freakiness... no, I don't think I will!"
'Hmpf, there I told here, not sure who she thinks she is to boss me around like that, fake owed favors or not'

Roulette lifts her eyebrow in an almost but not quite perfect replica of Lena's unimpressed-look "Are you breaking your word this fast, afraid you'll be stuck and unable to get out of them? You heard Elena, while these have are special to me as the originals, we've used the same many times."

"The House of El never breaks it's word! And pfft... no, I'm not afraid... it's just... I can't see through those and... well, I'm feeling very unsure now, ok. I don't like it"

Carrying the chastity belt over to Kara, roulette pats her with her free hand and scratches her scalp as she did in the basement "Oh my poor little pet, you don't have to be afraid, there's nothing in here that can hurt you and while I'm sure my word isn't as good as the illustrious El's, I do promise that I won't do anything to harm you and make no changes to their configuration without your explicit consent and collaboration, until then hey'll just be on default, ok?"

'Ooh, she's really good with those head scratches... and there's no tell tale signs for lies, neither pulse nor pupils... so maybe she's being truthful... or you know, she's a sociopath'
"I... I guess I'll trust that... but the first hint of breaking that and all deals are off!"
Taking the metal contraption from Roulette and bending over, Supergirl steps into them and slides them up her legs, lifting her dress as she goes "Huh, these aren't as tight as they looked, how will they even stay on?"

"With this" Roulette takes a power-tool with a weird complicated-looking head from a nearby table, sticks it in a hole in the right side of the metal panties and there's a sudden whirring sound as they tighten around her pelvis, Supergirl's eyes going wide from the way the tool makes everything vibrate.
Once she pulls the tool out, some inner mechanism snaps a cover shut over it, she then does the same to the other side, however, as she finishes the tightening and pulls out of the left hole they keep on with their low level vibration.

"Wha... why are they shaking... you said you'd not do anything!" the hands that had been holding up the dress now moves towards the chastity belt, but Roulette quickly places her hand on Kara's, and while she wouldn't have the power to even slow her down, just that touch stops her instantly.
'Why am I letting her control me so easily... and Rao these things are insidious... I have to make her turn them off... or take them off!'

"There there pet, I said it would remain on the default configuration, and in that case that is permanent edging, don't worry though that can be changed, if you're thinking of trying to get out of them you should know that this tool can't get it opened up again, nor can anything except my key which I don't have here."

Looking Supergirl up and down, Roulette's grin grows wider as she sees the frazzled look on her steadily blushing face and admires the way the dress tents over her breasts in a clear sign that the belt is already doing it's jobb.