A slang term used to describe women who've had an excessively high number of sex partners / high body count that makes reference to the quills on a porcupine.
"If she had as many dicks sticking out of her as she's had stuck in her she would look like a porcupenis".
When a man has used so much product in their hair that in retirement his hair is permanently spiked backwards giving off the appearance of a porcupine.
Where you and your girl are having sex with a porcupine, a game is played where whoever by the end of the sex has the most quills in the ass is the winner. The winner usually gets bragging rights to their parents as the intercourse is usually insestual.
John: ye ye bro me and Cheryl were porcupining!
Sam: yooooo! Please tell me you won.
John: of course I did dad you know Cheryl follows mom for her inhability to porcupine.
Sam: that’s my boy