Literally a combination of the expressions, "What the fuck?" and "Fuck you!/.," used(and not limited) to express both confusion and outrage. What the fuck you can also be abbreviated as WTFY(...), wtfy(...), or a have various combination of misused capitalization and spelling for a more bizarre tone(i.e. WtfU, etc.). WTFY can be expressed with an emphasis more lenient on outrage by first ending in an exclamation point, or to express more confusion by first ending in a question mark, both optionally followed respectively by their counterparts, or more of the same.
13.99 shipping and handling? WTFY!?
John: "Hey honey, I don't know you but I'm gonna try to be as obvious and degrading as I can to point out that I find you sexually attractive and my motive is to use you as an object."
Jane: "What the fuck you!?"
Brosky: "Hey dad, can I like borrow 400 dollars for my bills?"
Father: Puts down newspaper, "What the fuck you son?"