Dumbest thing you've seen a CFI do

With all the unemployed CFIs, I feel we should all talk about some of the dumbest things we've seen CFIs do in our career, to give them ideas of how to be a good CFI,

I'll start, I started at a new school for my CFI training, and I walked in for a lesson and saw an instructor showing off his fake ID at the front desk to other instructors.

https://redd.it/1x4lnsz
@r_aviation