The act of
flushing a toilet after you used it, and then unknowingly flushing it again while it is still flushing, resulting in a failed flush attempt and
a hollow flush sound. However, if for waiting 9 seconds, the crap is still in there,
Double kill it.
All the other men stared awkwardly at Bob when he went for a
double kill in
the urinal. Why would he double kill? He wasn't
crapping. It was completely unnecessary.