By the way, in the rifle company my son was assigned to finding a racial, ethnic slur attached to you was a sign of acceptance. Conversations were often more than politically incorrect, at least at the level of corporal and below.
My Marines had lots of politically incorrect conversations. Usually pretty hilarious. But I can understand a black guy not wanting to share a room with a big confederate flag on the wall. The light green corporal should have taken it down when asked.