ATL "Housewife" -- Don't Call Me a Crack Whore!

Reality catfights are all fun and games -- until somebody drags children and crack into it.

Lisa Wu Hartwell from "Real Housewives of Atlanta" tells TMZ she did leave a threatening voicemail for her rival co-star-- but only because Kim Zolciak called her a "crack whore" and insulted her children.

Lisa admits she lost her temper, but believes Kim -- the one who dated "Big Poppa" -- is using this minor incident as a catalyst to become the next reality show Z-list celeb.

Hartwell says there's no hard feelings -- as long as Kim leaves her children out of the mix. In other words, "Keep my name out ya mouth!"