The managers offices have windows that look out onto the main floor, I'm a training officer and sometime supervisor so although I look in the windows before I go in I'm generally "read in" on anything going on so If the doors closed I dont pay it much mind unless the boss is having a closed door with a staff member.

I went to walk in the door and got it half open before the facility manager bodily slams it closed. He looks out the window and sees its me, and says "Learn to knock!" gives me some paperwork to chase up.

3 minutes later I come back with paperwork, he is sitting there back to the window... with his coffee. I made eye contact with the other supervisors and went full cheshire cat. I waited till he lifted his cup and I closed fist pounded on that door like I had a fucking warrant.

He came about 3 inches out of his chair and wore the whole cup.