My old man(father) and uncles used to say this to me when i was a kid and beyond...hope my polish spelling is right-----" nie udawaj greka "......which obviously means don't act a greek,...........so my question is???are greeks gypsies,or does it imply something else ???or would they have said it to me because i was a smartarse(aussie slang)know-it-all !!!
Don't act like you don't know/understand what's going on.
It's usually used when a person is trying to pretend that she doesn't know anything.For example when the kid tells you that he doesn't know who ate all the sweets or when parents are yelling and the kid is all "but why are mad"