At first, she might just be putting on a show for her partner, bent over with her butt shaking, which is soon followed by removing her shorts and stockings. She exposes her anus, flexing it repeatedly, when suddenly, a slow stream of feces starts to seep out of the hole. As time passes, the flow of excrement only grows stronger.
She creates a massive mess on her underwear and all over herself, changing positions multiple times. Once she can no longer release any more, her anus and legs are covered in her own excrements, spreading a lot of it all over the floor.