Your sister caught you sniffing her used toilet paper and is disgusted and angry. She threatens to tell your parents, but then has a better idea. She thinks she is gonna make you suffer. "come here and stick your face in my asshole if you love smelling it so much!". She then notices you starting to get a hard-on. "whoa.. I didn't realize you were so twisted!" she says. "I'm gonna have fun with this.. let's see how twisted you are! You're gonna do everything I tell you! Stick your face in my shithole and start stroking that cock.." She spreads her ass and teases you, making you lick and sniff her asshole. Then she orders you to lie down and squats over you, smothring you with her ass. "Look at that asshole! Stroke your dick faster while I shove my shithole in your face!". Finally she tells you if you are good and cum exactly when she tells you, you can cum all over her asshole, since you love it so much