The act of cocking the foreskin of ones penis, similar in fashion to cocking a pump action shotgun. This act is often performed prior to taking a piss and shouldn't be confused with masturbation.
This is a sexual act where you first spank an ass so hard a bright red handprint shows up. Then you wack your flaccid penis on the handprint until erect and immediately ram it directly into the receivers asshole
Its when you are fucking a chick doggy style and you pull out your dick right before you are going to cum, place it on the top of her ass crack, then run a line of gunk from the top of her ass to her clit just like a caulking gun. This of course would also apply to the upper lip, forehead, ear-to-ear across the eyes, ect.
"I just laid a smooth line of baby batter on my girls ass crack with my cocking gun".