Well, yes

It was relatively warm down here, but after it felt like an hour went by Cindy started to shiver a little and the metal cuffs became quite uncomfortable. Cindy's knees were hurting on the hard floor, although she changed position a few times. Not that she had much room to move at all. Her sister should have come to look for her by now, or not? Cindy asked herself. Her mouth started to get dry, and her saliva was all over her, running down on her throat to her chest. After what already felt like 5 hours to Cindy, she could hear the door open and close again. "Mom said I should bring you some water." She could hear Brenda say and followed by that came a "click" sound of a bottle cap. Cindy figured her gag would be taken off for her to drink, and thoughts were forming what she would say to her tormentor. "You really thought I would let you drink that." Her sister laughed. "You can sure last some more hours without a drink or not?" The only thing Cindy could do was giving muffled cries into her gag as her sister emptied the bottle over her head and back, drenching her with the fluid. "She also gave me some treats to bring because she felt bad for you, but I don't think you deserve them, at least not your mouth." And with that, Cindy could feel a rough hand shoving something like a biscuit up inside her pussy. "Wow, you're actually wet, are you getting off on this? You little slut!" Cindy shook hear head and screamed into her gag to make clear she did not. But deep inside her, she knew there was something odd, a weird tingling feeling about her situation. "My sister is a little whore, I can't believe it. If mom finds out about that, you're gonna be in big trouble. Sadly, I can't tell her yet because she would probably know I touched you down there, I guess. Hm... But I got an idea how she will find it out herself. "Cindy felt her sister rub something rough on her clit and struggled to escape this humiliation. "Yea hump it bitch, that's the best video I took so far for sure hahaha" Brenda laughed. Cindy felt another two biscuits stuffed up her slit and some hard slaps directly on her bare pussy. "See you soon, horny bitch." And the door slammed again.