When you are so certain of something, that you will suck dick if you're wrong. Only works for
guys.
Generally used to
stop innane arguments when
one ignorant person keeps arguing something they know nothing about and you know that you're right.
"Isn't the Pub on the next street?"
"No,
dude, it's on this
one."
"I'm sure it's on the other street."
"Well, I'm SD Sure it's on this
one."
"Whoa. Okay, then. First round's on me."