When you have a runny nose and use your snot and fingers to play with a females clitoris without her knowledge, then placing your fingers in said females mouth to re-lube for more clitoris diddling action. This is all done AFTER using your tongue, never use if you plan to keep using your tongue. Sex afterwards is mandatory though.
A penis (size doesn't matter) that has surpassed the expiration date. Usually pretty dank and smelly, and always extremely hairy. Usually worn by old men.