A John Wilkes Booth is a thing of beauty. All circumstances must fall just right in order for a successful use of the word. While recieving a handjob inside a movie theater, the job-ee angles himself to cum on the back of the head of the person sitting in front if him, preferably with a beard. If your load hits the back of their head, you are a master. You've just completed a John Wilkes Booth.
"Dude, so I went to see Twilight with my girl last week, it totally sucked but she felt bad and gave me a handie. I John Wilkes Boothed ALL over the guy in front of me."