Nowadays, a dealer who sells heroin almost always sells crack cocaine too, and vice versa. And because dealers are so paranoid all the time about getting caught by the police, they don't appreciate users blatantly asking them for drugs by their names heroin and crack. This is especially true when talking on the phone as they always believe the line to be tapped by the police.
So from the colours/slang terms associated with the two drugs, i.e. brown for heroin and white for crack...
Brown has become Brandy and...
White has become Whisky.
Joey:yeaaaaa send it to me on my phone!
Brandy: ok hold on got to get my boobs in the right position.
Joey:ok hurry before my friend gets the phone.
Joeys FRIEND:omg dude joey you just got a picture of brandys boobs on yor hpone your girl is a whore.
Joey:ughhhhhhhh brandy i told yout o send it faster.
Joeys FRIEND:now im goign to tell the whole school.
Joey:no dont i will have ot break up with her.
Joeys FRIEND: oh well.
joey:im brekaing up with her.
Joey: brandy babe i have ot break up with you.
Brandy: no its not my fault im a little UGLY ASS CUNT!