My PC keyboard had got really dirty once so I decided to clean it. I took all the keycaps off and was cleaning them one by one. It wasn't long before I had an angry supervisor shouting at me. Soon after that, the department manager heard the commotion and came across to join in...
Them: "WTF are you doing

!"
Me: "You can see what I'm doing!"
Them: "Why are you cleaning your f***ing keyboard

!"
Me: "Obviously, because it is dirty!"
Them: "We don't pay you to f***ing clean f***ing keyboards

!"
Me: "It's become a health hazard!"
Them: "Well chuck the f***ing thing out and get a new one from the IT department then

!"
Me: "There's nothing wrong with it, it just needs a good clean. I don't believe in this throwaway culture. I'm cleaning it!"
Them: "WE DON'T F***ING PAY YOU TO F***ING CLEAN F***ING KEYBOARDS

!"
Me: "AND YOU DON'T PAY ME FOR THE 90 MINUTES OF OVERTIME I DO EVERY EVENING EITHER, NOR FOR THE 6 HOURS I DID WHEN I VOLUNTEERED TO COME IN LAST SATURDAY, NOR FOR MY RAIL FARE THAT DAY. I'M NEARLY FINISHED CLEANING MY KEYBOARD. YOU DON'T PAY ME TO SIT AROUND ARGUING WITH YOU EITHER!!!"
They gave up at that point...
Just recounting that story reminds me why I will never work in an office again

!