Asking what a mate has been smokin' cause of them acting strangely, jokingly mocking them of being stoned by drugs.
Person 1: Hey, bro! Did ya see bob the builder this morning? It's totally the shizzle.

Person 2: What have you been smokin' man?
by Dizza12 April 5, 2010
Get the What have you been smokin' mug.