Something was dropped onto the table near Lisa. instinctively, she turned her head towards it, despite being unable to see.
"You should drink something.", Kathy began and poured a glass, "I'm planning to gag you and I don't want you to dehydrate."
Lisa nodded in agreement and waited for the glass to touch her lips and Kathy's soft fingers her chin. She tilted her head backwards slowly, drinking the entire glass of water in one go. Kathy's fingers gently wiped the corner of her mouth before the glass was put aside.
"Okay, then, do you have anything left to say?"
"Yes. Please make it tight."
A rare chuckle left Kathy's lips.
"Oh don't you worry about that. Open up."
Lisa readily opened her mouth wide and it didn't take long for her captor to shove a large ball of fabric into it.
"Just so you know, those are my silk panties. So I hop you appreciate my sacrifice. Wider."
Lisa opened up a bit wider and felt the fabric being pushed in deeper as a large rubber ball was pressed behind her teeth and buckled up tightly.
"Everything all right so far?"
Lisa nodded with a muffled response. Next, the ripping sound of duct tape filled the room. Lisa, knowing what was coming, raised her head a bit and held still. The wide piece was carefully placed over her lips and the gag and pressed on securely. Two longer pieces followed that extended to her cheeks. Kathy's fingers touched her captives's cheeks carefully and she pressed her lips onto the part of the tape that covered her mouth.
"Mwah~!"
Her hands retreated and for a moment there was silence. Lisa took the chance to moan and scream, surprised at how little the combination gag actually let through. Her jaws were forced apart, she suspected that Kathy had chosen the largest ballgag in their collection, her mouth was completely stuffed with the panties and the tape tightly clung to her lips and her skin, constantly reminding her that her mouth was sealed shut.
"That should do it, don't you think? Or do you want more layers?"
Lisa shook her head, completely content.
"Good. Then, next, I think..." Kathy sat down on Lisa's lap again, her hands gently touching her captive's breasts. "I'll play with you a little bit."
Her fingers moved over Lisa's chest, carefully caressing and pinching her hardened nipples through the thin fabric of the straitjacket. Lisa tilted her head back, moaning contently, her body straining and wiggling, feeling the bonds and revelling in her own helplessness.
One hand stayed, slowly going from caressing to fondling, while the other moved down to Lisa's belly. Kathy's fingers danced around her belly button, feeling the navel piercing through the fabric. She stopped short of reaching her crotch.
"You already made such a mess, you're all wet... it's too bad there's a strap here."
Kathy touched the crotch strap that covered Lisa's lady bits. Realizing what that meant, Lisa complained as best as she could and thrashed in her bonds.
"Sorry but it's buckled in the back, so if I want to remove it, I need to untie you from the chair first and we don't want that yet, do we?"
Lisa complained again.
"I have a much better idea. You be a good girl for a few minutes and endure. Then I'll reward you, okay?"
Lisa sighed, mainly through the nose, and nodded.

Kathy allowed the torture to continue for a while. The increasingly frustrated moans from her roommate also pushed her further, making her start to finger herself, leaning forward and moaning provocatively into Lisa's ear, making the poor girl scream in frustration.
After some more minutes, though, she finally decided to show some mercy. getting up from Lisa's lap, she moved behind the chair and loosened the ropes, tossing those that had bound the straitjacket to the backrest aside. Lisa sighed in a bit of relief as she could finally lower her legs and lean forward. One by one, the tight ropes around her legs slipped off as well. Helping her up, Kathy checked with Lisa if she was doing okay and then led her over to the wall, pressing her against it after loosening and opening the crotch strap.
"You did good holding out this long." Her fingers moved up the inside of Lisa's thigh. "Here's your reward."
Her fingers slipped inside, making Lisa shiver and moan loudly, pulling at her arms and bending her upper body. It didn't take long for her to give in and cum, breathing a long sigh and leaning against Kathy.
"Sorry for making you wait so long."