For me it’s when they open with “you people”. When I ask them for information and they say something along the lines of “just look at your screen”. When I give my Great Day greeting and they say something like “well it’s not a great day here”. After they say that they’re usually rude and condescending. I’m generally empathetic to the problems customers have but there are some things that customers can say that literally make me lose every single f*** I once had.