I'm pretty sure this goes beyond a pet peeve

Let's get this on the table. Prejudice isn't, has never been, and never will be funny. So, when we are walking around the place that was a hell on earth in a way you will never experience, don't laugh. Don't pose and take silly pictures with your friends. Don't jokingly call each other racist slurs, when that prejudice was responsible for half a million deaths where you stand. I believe all opinions are valid in that what you believe is what you believe, but prejudice is not something open for debate. It is an abomination.