A regular in social media and journalist parlance, used to express disbelief at comments or actions that stand on pretense. Alternatively it is a barb or quip used to lampoon pretentiousness when in any way detected from an interlocutor.
"When I heard that the arts minister hadn't heard of the French new wave, I choked on my latte"
Very widely used in the South West of Sydney.
A "yougan" is an aboriginal creature from the dreamtime that would always ruin a corroboree (telling of a story through dance).
So when someone ruins a story or tells an unfunny joke they chucked a yougan!!
Joe: Where are you going Bill Bill: I'm going to your aunty's house for sex
Joe: My aunty just died
Sam: Bill, you just chucked a yougan