The act of unwillingly having a sticky wet mess left behind on your genitals after receiving oral sex. Most often perpetrated by a partner that uses too much slop and refuses to swallow. Also refers to the drool puddles left running down your sack and ass crack by said perpetrators.
" i thought she would have a pro head game, but left me a victim of knob slobbery"
1. A euphemism combined with a metaphor: Knob: euphemism for dick head, penis (cf. "get my knob polished"). Slobber: visible pre-cum (pre-ejaculate fluid) emanating from the penis, so called because the fluid is clear and visually resembles drool or spittle.
2. By extension, knob slobber can also mean a dick head bearing visible saliva (spittle) from fellatio, together with pre-ejaculate. The combination of the two is also clear.
A related term is knob slob, a giver of messy blowjobs.
--"Timm pre-cums so much his knob slobber looks like a deluge."