VERY good point. He didn't seem shy talking about such personal things--things that would humiliate anyone. I was shocked at his lack of respect for her privacy!
I think his only reason for mentioning it was to try and make Terri repugnant to listeners. I know that sounds awful, but I think it was part of the script and that was exactly the purpose for which it was designed. Felos is into mind games and psychological manipulation. I don't think the HINO came up with that on his own.