So would "go, and sin no more" count? As an alternative to "go, and be good", maybe? Oh my goodness, I think we may have a literary grey area here. If someone who misbehaves regularly, a persistant malefator, a recidivist (some nice long words for you!) decides to be good for a while, he can say, without understatement (i.e. not litotically), "I ain't misbehavin'". (Bad guys tend to talk like that.) Onthe other hand, a faithful lover, with some literary pretension and a sparkle in his eye, might prefer to says "ain't misbehavin'" in preference to "am behavin'"; or "being faithful", if he wanted to be prosaic. Must be a contextual thing.

Steve

P.s. Podger--we're not really analysing songs, we're looking for an excuse to fight!