cappin' the rap! (Bad Language)

[SiXSwordS]

From cecil’s column on signifying:

A key objective in ritual insults is to have a snappy comeback, commonly known as cappin’ the rap. If somebody says, “Screw you,” you say, “Hey, man, we ain’t even kissed yet.”

My favorite example of this is:
Person A: You fucker!
person B: You Fuck 'er, you brought her!