Someone who Flugs/is a Fluger uses to much time in the bathroom, restroom stall, ect. Not doing normal thing. They would be doing anything from jacking off, to eating whole fat yogurt. And anything in between.
Person 1: Other people need to use the bathroom to ya know!?
Person 2: Hold on!
Person 1: You stupid Fluger!!
Person 2: I'm not fluging. I'm pooping!!
Person 1: Go jack off in your office!!