When a man (or a lady donning a strap-on) unknowingly hijacks a small piece of poo from anothers anal region upon removal of their pleasure tool.
Right, Matt you need to have a word with your dad because I've picked up so many shit boogers off him my penis is starting to look like a choc-chip muffin.
When a man partakes in anal intercourse with another person, and apon withdrawing, discovers a "booger" of excrement on the end of his penis.
Hey Tom! I've still got a shit booger on the end of my cock from when I fucked your mum last night!
Shit Boogers are found the morning after a night of having your nose in a girls butthole. When you sneeze or pick your nose in the morning and find a little piece of poo....this is a shit booger. CONGRATS! You just got your first case of shit boogers!
I woke up this morning and remembered that I 69'd with my girlfriend last night. While engaged in the act, I stuck my nose up her butthole for some odd reason. Then I sneezed out some Shit Boogers