Donkey: "Oooo, Shrek, did you just do that? Man, you oughta warn someone when you crack one like that!"
Shrek: "Believe me, Donkey, If that had been me, you'd have been dead. (*inhales*) It's brimstone."
To lascerate your cock while 'watching videos of/imagining/looking at photos of/in the presence of' hot sexy women.
Masturbation in laymans terms.
James: "Im going home for a wank."
Tim: "haha, james is gonna crack one out, the randy bastard, remember to clean yourself up, and your mums back, dont be rubbin the cum into her back too much again".