When men are trying to be men (growing beards, chopping wood, drinking whiskey, etc.) and there is an onslaught of a large amount of annoying, often mediocre-looking girls. Very negative connotation.
Dude, we tried to go bowling last night but Diego invited a massive poonvasion. They just were drinking long island iced teas and made us use bumpers. I wanted to vomit.
by Bonesauce December 25, 2009