Aggressive anal pumpage (AAP) resulting in a holy mess in the form of copious bodily discharge.
"Stuart and Paul, the local benders, were caught sludging in Tesco's carpark the other day. The dirty bastards."
The oh-so-lovely process that sometimes occurs in females about 2 weeks after their periods, in which left overs from the previous period leak out. A sludgy, dark-brown discharge leaks from the vagina and frequently stains underwear; making them look suspiciously shit-stained. Though the flow is not as heavy as a regular period, it is still damn annoying.
I had to go out and buy new underwear because they were stained from all the sludging yesterday.