"COMEDY BEGIN

I met a guy in a cave in the middle of the night, having a nose bleed he was. I offered him a tissue.
(translyvainian accent) "Ahh, thank you", he said, "But I do not currently suffer from a nosebleed. I am a vampire! I love ah blood! Aha!"
No, I said. Vampires suck blood, not piss it out their noses.
"No, man, I was feeding on this one guy in his own living room and I noticed he had flashdance on DVD and I pissed myself laughing"

Then I noticed he was crying.
"I vantah to stop feeding off people, but all the guys at work make fun of me for feeding off animals like one of those twilight pussies, even though animals actually fight back harder than humans. I tried to feed off a zebra once and he kicked me. I said you just a zebra right! and he came over to me and said:"
(Johnny Rotten Cockney accent) "Mohawk, knocking around in antisocial crowds, naw mate, imma little kitten."
(pause)
"Vhen he started to pogo me to death!"
(you jump up and down whilst reciting OI OI OI)

Ahh I see, I said. Do you want a tissue for that broken arm as well?

(or other horrific injury that's funnier than a broken arm and more visual than a nosebleed.)

COMEDY END"

What

Does "piss myself laughing" have a different meaning in Britain than it does in America?

5 for "or other horrific injury that's funnier than a broken arm"