When someone rubs their scrotum against a dock (mostly wooden ones), which boats tie up to. These are the most sick and twisted people you may ever come across. They will not stop scrotum docking! Not even if their scrotum looks like a sea urchin from having so many splinters in it!
( ex. 1 )
Cameron: ewww! look at that guy, why is he doing that to the dock?!
Jack: because he's a scrotum docker!
Cameron: if he gets a splinter there, wouldn't it hurt?
Jack: no, because his scrotum is very rough and tough skinned now from scrotum docking so much...
( ex. 2 )
Eddie: Is that a sea urchin connected to that guy?
Garrett: No, thats just a guy's scrotum after scrotum docking.