Verb. Perform an upgrade/update for or to a system if it is installed. If it not installed, perform an install. Similar in semantics to the word upsert.
An individual whom follows package delivery services around during the holiday's seeking out opportunities to steal boxes that are left in front of houses by the driver.
"Dude, me and Bob did a little UPStalking yesterday and nabbed a new PC thanks to the dork who left the box at a vacant house."
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi