The mandatory smoking rotation of a group of people, especially for weed blunts or joints. "Puff puff" means you take two short hits (usually the required limit), and "give" means you hand the smoking device to the person next to you in the rotation. This phrase was made popular among ignorant white kids by Chris Tucker's character Smokey in the 1995 movie "Friday."
Look at this faggot trying to take an extra hit. Puff puff give, motherfucker!