When you go to someone's house for a party and the flush is not working properly, different people's poo get accumulated in the commode. In the end, it just seems like various people have contributed to the poo in the bowl - hence 'potty luck'.
Yesterday, I organized a pot luck party in my house without realizing my flush wasn't working properly. By the end of the day, it seemed my bathroom had hosted a potty luck.
by K-905 January 29, 2011