when a person (or persons) enters a state of anti-sobriety in which they confuse an unacceptable pissing location (i.e. a closet or suitcase) for an acceptable pissing location (i.e. a toilet). Piss confusion often occurs in a sleep-walking state, following an evening of excessive consumption of wine, beer or spirits.
"Me and my buddy drank 40s all night and crashed. Two hours later I woke up to the sound of my buddy peeing in his open suitcase. Yep, classic case of piss confusion."