One of the most useless things to use in conversation. Adds nothing and is utter cop out. A proper kick in the teeth would be a most polite response to such dribble introduced in dialogue.
"Jess Sayin.." yeah, ya dumb c*nt, I can hear you running your stupid f*ckin' mouth,
no need to remind me of the fact that you're "jess sayin". How about "not sayin'" and
sparing me of your stupidity and utter lack of thought and creativity in phraseology...jess sayin.