At work, i locked the door and took of the lid to the cistern (the bit that controls flushing). I added some bubble bath and some pink food colouring. I put the lid back on, walked out and hid in the next cubicle, waiting for my 1st victim.
The first person to go in didnt flush the toilet so I carried on waiting.
Finnly my boss came in, took a crap and flushed the toilet. Lots of words were said as pink bubbles emerged from the toilet and started going everwhere!
The cleaners were called. They were puzzled why this had happened and started undoing the pipes leading to the toilet to find out what caused it. They still dont know!
(I hope my boss doesn't read this!)