|1.||Saliva Buffer Zone|
The part of an item of food you and a friend purposefully don't eat when sharing said food item, as to not accidentally ingest some of the other other's saliva. Thus preventing the spread of germs.
Mark: "Dude can i share that piece of pizza with you? I'm starving.... "
John: "Sure... I guess, we just have to be sure to leave a saliva buffer zone..."