Ok, so this technically isn't a Flash game, but I HAD to share this:
Amazing Virtual Pee Experience from Japan
As any good geek should know by now Japan has some of the wackiest and most unusual products anywhere. So when we were visiting Tokyo recently and saw lines of Japanese schoolgirls waiting to play an amazing new game for the Wii called Super Pii Pii Brothers we were only a little surprised. After all with games like WarioWare and Raving Rabbids the Wii is no stranger to crazy gameplay mechanics... but it was quite unusual to see the "strap-on" style accessory and peeing action that Pii Pii Brothers provides. Normally ThinkGeek doesn't carry video games, but we were so blown-away by Super Pii Pii Brothers that we immediately got our trusted Japanese importer on the phone and arranged to bring over a limited quantity of this amazing Wii game along with some cross regional boot discs to allow play on USA Wii consoles.
The play mechanics are simple. Prepare yourself by strapping on the included belt harness and jacking in your Wiimote. A series of toilets are presented on screen and the challenge is to tilt your body to control a never-ending stream of pee. Get as much pee in the toilets as you can while spilling as little on the floor as possible. Sounds easy eh? Well the toilets open and close whack-a-mole style and occasionally the stray cat or other cute critter pops up. Spray a cat for extra points. Get too much pee on the ground and your game is over. With realistic fluid dynamics for the pee and over 100 different bathrooms from bars and palaces to automatic Japanese style toilets you'll be entertained for hours. And wait until your friends see the multi-player mode with dueling pee streams...
According to the Japanese text on the box "Super Pii Pii Brothers promotes good bathroom skills and allows women to experience for the first time the pleasure of urinating while standing." What we say is that virtual peeing is damn fun!