Krassenstein

The stain on your underwear as a result of sharting, sometimes permeating to the outer layers of your clothing. Usually accompanied by a putrid odour. Biohazardous.

I thought I just farted, then I checked my underwear and saw a huge krassenstein.
I could smell the krassenstein as he took off his trousers.
As I walked into the room, the dog ran straight to me and nuzzled my krassenstein