A catastrophic event or injury caused by improper use of a wiimote. Putting the wiimote through a window or TV, striking a friend or pet, any one of these can be a wiitastrophe.
Kyle didn't put the wrist strap on to play tennis. He went for an overhead smash to win the match and lost control of the wiimote which hit his plasma TV. The TV then fell into his fish tank, breaking it and sending a tsunami across his basement which drowned his cat. It was a wiitastrophe.
When a person surreptitiously gives their sexual partner a dirty sanchez by giving himself a dirty sanchez in secret and then kissing their unknowing partner thus applying the sneaky sanchez to their upper lip without them knowing.
Kyle smeared poo across his upper lip before his wife came home from work. Giving her a big kiss as she came through the door he applied the sneaky sanchez.