I work in a 5 star hotel bar. A few weeks ago, I had a customer come in and be an absolute prick to me infront of other customers. When he was about to leave, the conversation went like this:
Me: *muttered under breath, loud enough for him to hear* Fuckin' idiot
Him: WHAT DID YOU CALL ME?
Me: You heard me asshole, I called you a fucking idiot.
*Other customers snicker*
Him: I WANT TO TALK TO YOUR FUCKING SUPERVISOR!
Me: Go for it, she's right here. I don't care.
He started swearing at my supervisor and called her incompetent and was being really racist to her (she's Thai). Either way, I thought I was going to get fired for swearing at a customer but I didn't. Turns out that this dude was staying in the hotel for the next 10 days. He came in another time at a later date and I was working, he saw me, ordered a drink quietly with his head bowed down as I stared dead straight at his eyes. He just avoided my gaze, charged the drink to his room and even tipped me and went elsewhere to consume it.