When someone closes or flutters their eyes whilst talking, presumably to show how intelligent they are.
When someone is so up their own ass that they close their eyes to make a point during a conversation, making them look like they have epilepsy.
Guy 1: So what did you think about the discussion on global warming last night?
Guy 2: I try <flutternot to engage in such trivial discussions about the inevitable.
Guy 1: Dude, don't be such a fluttercunt.