Speen can be a nickname given to those who exhibit an uncontrollable, hyper, ninja like personality usually brought on by alcohol. It can also describe one's ballsack.
Dude!! Get this freaking Speen off of me, he's hammered!!
Hey, I can see your Speen under those jorts
The act of peeing in the morning after a long night of nastiness and having your pee split into two uncontrollable urine streams that drench everything in the restroom as you wave your hips from side to side in a feeble attempt to get some into the toilet.
Bobby: Holy shit I just soaked the rest room with my split stream action bro....im so sorry.
Tony: Its cuz you were messing with that Mcnasty Sheeat all night and your tip is welded shut
The act of quick double taking to look at an exposed "crack" resulting in a strained or hurt neck
Tony: Dude, hurry and check out Dianne!! She bent over the counter!
Bobby: Where...Aaaghh...I turned too fast and got whip crack!