Skull Ducking 

Skull ducking is an ancient myan sport which involves tapping someone on the skull with the bill of a duck. Whoever can withstand being ducked for the longest time win. Although it is quite complicated and it involves the flexing of certain skeletal muscles to make the skull ducking last longer.

Recently, has been recommended by some that it should be an olympic sport.

We skull ducked for hours.
I Skull ducked your grandmother.
I dipped the remainder of my penis in a shit covered, hairy bloody, egg smelling, tuna infested, bubbling, vaginal puss farting hole after we were done Skull Ducking Your grandmother.

Skull Ducking by The Brave Little Toaster June 2, 2009

Skullfucking 

1. Quite literally, to fuck in the skull. This usually means inserting one's penis into any orifice in the head (excluding the mouth), such as the nostrils, ears or a hole bashed into the back of the head with a pair of pliers. As this is not only rather painful but quite impossible in most cases, skullfucking is not a common practice in real life (unless you're talking about necrophiliacs that is). It is, however, tolerably prevalent in the world of hentai art, resulting in pictures that are more horrific than sexually arousing. My advice: don't seek out any of these pictures unless you have an uncontrollable urge to lose your lunch all over the keyboard. See also skullfuck.
2. See mindfuck.
3. Can also be used as a kind of insult.

1. I love skullfucking ^_^
2. Damn, watching Memento will give you a bloody good skullfucking.
3. Skullfucker!

Skullfucking by Fooby July 24, 2004

Skullfucking 

To hold the recipient by the back of the head and insert one's penis into another's mouth forcefully and deeply. Most likely giving the skullfuck-ee less enjoyment than the skullfuck-er.

Skullfucking is fun until someone loses an eye...

Skullfucking by Tim August 22, 2004

skullfucking 

the actof forcing ones penis down a willing females throat , often leading to severe gagging but obvious enjoyment on the part of the female participant

"I skullfucked her till her spit ran down my balls"

skullfucking by JS Michaels November 23, 2003

Skullfucking 

The act of hitting someone so hard in the head with your rock hard cock that it ends up penetrating their frontal lobe.

Person 1: Did you hear about that guy with the huge cock that went around skullfucking people?
Person 2: I heard he was a little bit of a dick.

Skullfucking by TearsOnlyMakeTheSaladFresher April 28, 2016

Skullfucking 

Skullfucking is a ward to describe repeatedly jamming your two inch pinch into any open area of the skull, (Eye Socket, Mouth, Ear, etc)

I was Skullfucking Jennifer last night, and my dick bled

Skullfucking by Ery's Toe September 17, 2016