I'd be upset too, of course. T once referred to my abuser (who is pretty much the entire focus of therapy) by the wrong name. I got really quiet and finally told him. He got very redfaced and apologized. It stung, but I did believe that it was a slip of the tongue.

It reminds me of how I had two best friends in college. We spent all our time together, lived together, etc. And I was ALWAYS calling them by the other's name. I felt stupid and bad because I knew it was insulting, but my brain seemed to always get the wires crossed.

A mistake can be innocent and accidental, and yet still hurt. It's okay if it's both.