First, encase her in a latex bodysuit

Duromast stands and walks around the young sex ****, admiring his handiwork. Occasionally he reaches out, lifting one of her huge tits, feeling their weight and soft malleability while deciding what to do next. Finally he nods to himself and walks across the room to the wardrobe, motioning for Cinnamon to follow him. She stumbles after him gingerly, both hands holding her still sore tits to keep them from swinging painfully. Her balance is completely off with the thirty pounds of tit flesh added to her chest and nearly falls twice just walking across the room. As soon as she catches up with the demon he hands her another jar of oil saying, "Here, grease yourself up with this."

Cinnamon takes the jar in a trembling hand and carefully begins to rub the slick oil into her light brown skin, worried what effect it might have on her. Fortunately for her it's just normal lube, though she immediately realizes why she needs it when Duromast hands her a small latex garment. She's never worn one of these before, but she's familiar enough with them that she's able to at least find the small slit in the back where she's supposed to slide into it. The demon just smiles down at her, folding his arms, leaning against the wall, and enjoying the ridiculous swinging of her tits as she struggles with the garment. After a few slightly embarrassing minutes she's able to get the suit on up to her shoulders. The tight body suit almost covers her completely. The front of the suit has two holes she had to struggle to pull her breasts through. Clearly the suit was made for someone as slender as her, but not nearly as stacked. As such the latex grips the base of her tits tightly, squeezing them like rubber bands, making them look even more swollen and huge.

The demon finally walks back over to her, pulling the latex hood up over her head encasing her in darkness. The hood has a single hole, just for her mouth but nothing for her eyes or nose. The demon runs a finger from the top of her head, down her back to the crack of her ass, the suit tightening and closing in on her like a living thing. Once it's on her it's like a second skin, tight enough that her big clit and pussy lips are clearly visible against the rubbery surface. If she bent over even the wrinkles of her asshole would be visible, imprinted on the slick black rubber.