When smoking weed from a pipe and a piece of the bud comes through the pipe and down your throat/windpipe. Which can cause you to cough and look like an amature smoker.
Stephan: Dude i thought you smoked all the time, you made us look bad in front of those guys.
Leon:Dude im good, it was a scoobie snack from your shitty, wack ass pipe.
Stephan: ... my bad.