A nod to the popular 90's rumour that Marilyn Manson had some ribs removed so he could suck his own dick. Though in this case the term is flipped and aimed at someone who you consider to be 'backwards', either in their thinking and beliefs or literally just doing something completely the wrong way.
"RANDY?? OH MATE, HE IS THE TYPE OF GUY WHO WOULD CHOP OFF HIS DICK SO HE COULD SUCK HIS OWN RIBS, HE'S A REAL RIB SUCKER"
"Yeah mate, Randy has a mouthful of ribs"
"Yeah mate, Randy has a mouthful of ribs"
by Beansinacan July 10, 2019