Autonomous anal fisting

"Alright slut. Time to see what you're really capable of." You say, pulling Mia from Tracy's asshole.

"Get on your hands and knees on the floor slut." You tell Tracy.

Tracy does as instructed and gets into position.

"Good girl. Now I want you to put your own fist into your ass."

"Yes sir." She replies, in complete subservitude.

Tracy reaches back behind her and slowly starts sliding her fingers inside her own asshole. With some struggle, she manages to contort herself and slide her whole fist inside herself. Her face is one of deep focus and ecstasy, the same face that you're used to seeing when she's pleasuring herself, but in this case it's from something as depraved as fisting her own ass.

Before long, Tracy is pumping her whole fist in and out of her ass and you can see that she's really starting to enjoy it.

"Oh fuuuck." You hear her mutter under her breath.

"Go deeper slut." You order her.

"Yes... sir." She squeezes out through drawn breaths as she contorts herself further to be able to slide more or her arm inside her own asshole.

After some hard work and serious stretching, both of her asshole and the rest of her body, Tracy has somehow managed to get herself almost elbow deep inside her own asshole. Both you and Mia stare on in shock and admiration as this slut performs an act that you never even would've thought possible before today.

"Holy shit." Is all you can get out.

Tracy takes a moment to shit from her face of deep focus to giggle and smile at you after your quasi-compliment. You and Mia watch on for a while, entranced by what Tracy is capable of until finally you decide to move on.

"Alright you two, time to get on your backs on the couch."

Tracy slowly slides the length of her forearm out of her asshole, releasing a satisfying pop the moment her fist comes out of her gaping asshole before getting up onto the couch alongside Mia.