The rules of the Thwap are:
A) A Thwap is performed as a joke
B) You dont Thwap someone you dont know..Ever
C) A Thwap is only a Thwap when saying "Thwap" as you Thwap... Got it?
Most often used when trying to exemplify how huge or great they are. So baps would be on one level but if desribed as "thwaps" it takes extra tongue dexterity to pronounce thus more effort thus ramming home the fact that these breasts were far out of this world.