When something is so unbelievable that the phrase "are you shitting me?" is not enough. It demonstrates that the action taking place, or the event being described is so monstrously horrific that it literally feels like someone is taking a massive shit inside of your chest. Basically, the worst feeling ever is happening, and at this point you're questioning why the fuck.
Douche: LOL I TOTALLY RAPED THIS CHILD WITH A PITCHFORK OF AIDS Person: ...are you shitting inside of me?
Douche: ...No? But I could be.
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. PenguinBooks,1992. p. 38)