Forensics Detective: "Hey, would you hand me that skulleton?"
Assistant: "What, just the skull, or the whole skeleton?
Forensics Detective: "Either one. You choose."
A superior form of masturbation done by making a light fist over the tip of your penis and squeezing while moving up. It stimulates far more than traditional masturbating and simulates oral. The name derives from the general shape of the hand while it stimulates the penis.
Dude I was skulltopping last night and I blew the fattest load of all time.