WWII-style
Sharing a single cigarette with someone by passing it back and forth after inhaling. The term comes from WWII soldiers who had limited quantities of cigarettes, and would share them this way with their comrades.
Mark: Hey, can I bum a cigarette off you?
Jon: Eh, I only have one left. Want to smoke it WWII-style?
Jon: Eh, I only have one left. Want to smoke it WWII-style?