When one takes the action of farting but then realizes that they actually just shat themselves, thus creating the sense of being surprised.
Ray decides that it would be funny to let loose odorous gas, but thenrealises he shat himself in his attempt making him surprised when he discovers brown streaks lining his undergarments.
It's the feeling you get when you've struggled with self loathing for years and when you try to find the meaning of your name, the typically most cynical and sarcastic place on the internet has the most heartwarming definitions for it. Thank you, Urban Dictionary!
- From an Ariana