I had to ban one of my longest term regulars just last night. It was a really tough decision. He has probably tipped thousands over the course of the past couple years. The more nice I am to him, the more he becomes assertive and aggressive and teasing. He started gatekeeping and comparing himself to other tippers, but most of all just had an aura of disrespect for me. It gets to the point where their tips and compliments don't do anything anymore, because you know they are a bad person.
So I banned them, and actually made triple the amount I usually make. I'm still stressed about the decision, and mostly because I was open about what was going on with my chat, because it was very visible that I was annoyed. He did this right around the time I did my goalshow, so I probably lost a few tippers as well.