The lousina purchase is when you hot glue coins to your dong and stick it in a girl's anal hole. All this is after you light her hair on fire. There is also another version called the screaming louisiana purchase when the same thing is done except you throw her out of a window when your done.
Dude, I pulled a lousiana purchase last night and now the cops are after me. Shit gotta go.
When a girl's ass transforms into a large mass and volume within a very short period of time less than 12 months similar to the immediate U.S. land expanison of 1803.
Dan: Dude, I don't know how her ass got that big. It was small last year.
David: Yeah, it was, that's a total Lousiana Purchase.