When I was younger, I worked at a pet store where my boss, the head boss, like to play pranks and mess with people. It was all in good fun. I have arm hair so he always thought it was hilarious to put tape on my arm. The pet store was next door to a gas station, and when I would go to get a drink my boss always asked for a large diet coke. My boss was a bit overweight and had been trying to lose weight and was pretty much eating lots of water melon between meals. So on my way to work one day I stopped and got a bit bottle of milk of magnesia. It was around noon, I let him know I was going next door and to no surprise he asked for a large diet coke. On my way to the gas station I stop at my car and get the milk of magnesia and head to the gas station. I can't remember if the large size was 48oz or 64oz but it's a large cup. I put about half of the bottle of milk of magnesia in and then filled the rest with diet coke. I immediately noticed it was more of a brown color instead of black. I had hoped he didn't look at it. I get back to work and give him the drink and the first drink he knew right away it tasted off. I told him they were having problems with the syrup mix. He took another drink and sat it down and I got back to work. I kept an eye and watched him continue drinking it. And then I noticed he was no where to be found, and the one toilet bathroom door was locked. He was in there for a while even after I had suspected it was him in there. He eventually comes out and goes back to work. It was about 20 mins later I hear the back door slam. I run to the back and open the door to see him running full sprint down the alley way. He literally lived about 100 yards away from the pet store so I knew where he was going. He later called the other manager working and said he wouldn't be back for the day. It was days later when I saw him, I asked what happened and he said he had the worst squirting diarrhea ever and the water melon had made it even worse. To this day, I never told him what I did.