A phenomenon commonly seen in the cubicles of cafe and restaurant restrooms, which have a tendency of not having urinals.

Someone walks in and takes a piss, hitting the toilet seat (whether by accident or on purpose, usually on purpose) and the janitor is unlikely to clean the piss due to being underpaid.

The next person walks in and sees the piss on the seat, and stands further away from the seat than the previous person for fear of touching the piss-covered seat.

Due to the increased distance from the toilet seat, the person is more likely to hit the seat with his piss.

Eventually people start hitting not only the seat but also the floor with their piss, leading people to stand further still from the toilet for fear of getting piss on their shoes, leading to an exponential increase in the saturation of piss on the toilet seat and floor and the distance people stand from the toilet, aswell as an exponential decrease in each consecutive visitor's stream accuracy and the likelihood of the janitors cleaning all the piss.

When complete saturation is reached, the janitors will either quit their jobs, commit suicide or make a prayer to janitor jesus to make all the piss go away. The latter option is usually how toilet seats are eventually cleaned.
I went to a public restroom today and the whole seat was covered in piss. Realizing that a toilet seat singularity was in play, I decided not to perpetuate the chain and to simply hold it in until I found a cleaner toilet or a urinal elsewhere.
by Fruitfly July 26, 2017
Get the Toilet Seat Singularity mug.