The FPI stands for Federal Penis Inspectors, they are a group of people who inspect penis' of all shapes and sizes and determine if they are microscopic.
FPI OPEN UP, SHOW ME THE SMALL PP.
A strong fondness of being urinated on in a sexual context.
"Bruthur, I was up late last night, the bedroom was getting boring so I got a golden shower and now I think I have peepeephilia"