FFIU 

Fat Fuck In Uniform. When you see someone in a normally fit uniformed profession in less than ideal physical condition (police, military, etc.).

"What happened to all the donuts?"
"That FFIU over there ate them ALL."

FFIU by Paladinski June 9, 2016

FFIU 

Fatty Fucked it Up

When a really obese person's ass bumps into something important and completely screws it up.

"What happened to your drawing?" "Oh, FFIU when she bumped into my desk."

FFIU by twilightz0ne May 14, 2010