Used to describe a low cost or disreputable rest home/seniors residence, as used in the popular sitcom "Golden Girls". Regular character Sophia Petrillo was kept inline with the constant threat of being sent back to "Shady Pines".
National Shit Your Pants Day, which takes place on April 28, is a regularly-celebrated holiday in the Midwest Region of America, most likely devised by clothing companies to sell replacement underwear and pants to partakers.
Thursday night I wore my white corduroy pants out to the bar. I didn’t know my white corduroys would soon become my shit pants. I got so boozed, I stole my friends shoes and barfed in them. Then I shit my pants...Thursday night I was Shit-Pants Drunk.