Have you ever noticed someone use a derogatory slur for either race or sexuality and then turn around later and say "I'm not racist" or "I'm not homophobic"?

After the company Christmas party I went out with my crew. We sat around the table talking for a couple of hours. The next work day they were talking about one of their's guest. They were all wondering if he was gay. I told them he was, but the person who invoted him said he wasn't and had asked him before and he denied it. That is when I pointed out he will never come out as long as she and her friends keep using the phrase "That's so gay!" as a derogatory comment. And asked them how many times they had said it that night. They all became very quiet. They never realized how that phrase could hurt someone. I never heard any of them use that phrase again.