Define Pileup Meaning

a collision involving numerous motor vehicles

Act where any number of lesbian women pile on top of each other for sexual pleasure. Typically involving four or more females but can grow to double digit numbers where the pressure on the bottom of said pileup reaching lethal levels.

Cincinnati pile up is when three or more men take turns shitting on a chicks face.

A bunnch of trumpsters blocking a motorway for some fucking reason.

The act of two males masturbating with one another and ejaculating at the same exact time. The result is the ejaculated sperm colliding with one another.
This should not be confused with a "San Franciscan Kiss", which is similar, but one male ejaculates into the urethra of another man during or before the other male's orgasm.

when a bunch of black asian homos lay on top of each other, motionless.

A type of orgy involving 20 or more drunken people usually in a Texas Holiday inn. It begins with a woman bent over the bed taking it in the anus . Then the other participants run with hardons or strapons into the asses of each consecutive person interlocking everyone ass to cock , cock to ass.