He performed at a friend's venue once and was apparently a massive douchebag, ordering everyone around thinking the world revolved around him. He also publicly berated staff over silly mistakes and even publicly berated the openers.
Ugh. My friend and I have a name for people like that - door pullers. It came from this one incident we saw while travelling for work where some rich dude started angrily pulling on the door handle of the car because his driver (his actual driver, like not an Uber or taxi) wasn't fast enough unlocking it.