1) short for "Shit You Say" normally punctuated as an exclamated question 2) credulity 3) are you serious? 4) forget that mess 5) Bullshit you are saying
its not always a question but is always punctuated with a the classic "!?" or "?!"
shitusay there was bestiality at the party?!; shitusay this is decaf?!; Arnold Schwarzenegger became Governor? shitusay!? that N-Word Jim ate all the waffels? shitusay, and you did not murk that fool!?