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.