Her asshole is gaping all the way with the help of the dildo, and a huge turd sitting in there. At first the turd helps her asshole gape really wide, and every time it tries to emerge, she pushes it back inside with the dildo. Unfortunately it gets harder and harder to gape since there's nothing holding back her shit, but she does it until the very last moment when she can barely keep the turd in. Eventually she can't continue because she has to shit so bad that the turd instantly starts forcing its way out when she tries to gape.
