I have one that happened to a good friend:
She's quite a prude [a total polar opposite of me]. Her and her fiancée were getting down and dirty for the first time- she usually lays there like a pancake. She was a little drunk and also had Indian food that night. While getting a double take of a vibrator and his manhood [yea I know WOW] she said she felt a slight pressure an just let out a fart. She ended up having a major case of diarrhea and basically sh--t all over him. Her fiancée was so disgusted he actually vomited everywhere, including on himself and her.
That my friend is probably one of the worst sexual experiences I have ever heard.
Eww [mental images]
Sarah

