This is a phrase generated in the country when someone says or does something so ridiculous, you can hardly think of a nice or unoffensive response. Many think that Chad Ocho Cinco of the Cincinnati Bengals made this up, but he just brought it back. My granny has been saying it for years and I bet his granny did too.
Me- Granny can I go over to Jermaines for dinner?
Granny- Child Please you know Jermaines momma don't cook.