The act of ruining an exceptional social gathering by "logicalizing" its various financial, managerial, or public relations benefits and or flaws. The aforementioned douching will then suck out all fun previously thought to be had at said social gathering.
Guy 1: God this party is kick ass, the keg is flowing and the bitches be bangin'.
Guy 2: Well you know (Guy 1), that keg has actually cost us quite a large some of money, 84.99 to be precise, plus tax of course. The possibility of many of these ladies being underage aside from the vast amount of sexually transmitted diseases that can be gotten from all the intercourse going on is quite taxing.
Guy 3: You are a business douche, quit business douching our party...ass.
A business person whose life revolves around money and work, and enjoys flaunting their wealth.
Tom has just bought a $200 dollar watch, and claimed it as a business expense. He is a business douche.