Instantly she felt a rumble in her gut. This passed through her body and came out as a gassy fart. However, the fart became more and more solid.
That was when she realized she was messing herself. The solid mess pushed itself out of her butt and into her panties. Once it hit her panties it started to squish around her butt a bit. After a little bit, she was done messing herself.
After that...