A stronger version of "you can't be serious", which can be subtle enough to pass without notice or delivered straight.
Boss: I'm cutting your hours back cos you slack off.
Jane: You cunt be serious.
Jack: I'm leaving you to marry your sister.
Shirley: Surely you cunt be serious.
Jack: I am serious, so don't call me Shirley.
Jane: You cunt be serious.
Jack: I'm leaving you to marry your sister.
Shirley: Surely you cunt be serious.
Jack: I am serious, so don't call me Shirley.
by GWMcL January 31, 2011