I worked with a group of people for a handful of years. A bunch of different nationalities, and at one point we were bored enough that we just started using the most horrible slurs to refer to each other in casual conversation. For a week or two it seemed to be fine, until one day there was some huge argument. One of us actually had been feeling pretty hurt by the ironic abuse and had finally had enough and when asking that we all stop or at least leave them out of it had got some pretty caustic push back.

Shit got intense for a day or so until we managed to just agree that since it stopped being "fun" to just not do it anymore.