"Using buddy" is a term used to describe an addict's primary partner in crime who is at the same level of addiction and decision making as the addict themself.
Using buddy can be a compliment among addicts "you are the best using buddy ever!", or a disparaging comment - for example if someone calls you a crack addict in a critical way because of your behavior, and you reply "fuck you, using buddy" to indicate they are the pot callint the kettle black.
by dancing panda April 19, 2009