Not to be confused with the jean noster, a knob noster is when a chick gives a guy a handjob using breast milk as lube. When the guy finishes, she cleans everything up with her mouth, then spits "knob noster" in his face.
When Allison was done giving Adam a handjob with her breast milk, she cleaned off his cock with her mouth, and spit knob noster in his face.
The act of taking a man's full load of cum by a female(or male) up a single(or both) nostril(s) & snorting it.
"Jesus, was that high priced hooker was worth every penny we spent for your bachelor partylast night, Rich! Did you see the way she could take a load of nostril snotch in one single snort! Wow, whatta professional she was!"