My T never asked me much about SI and if it was connected to sui thoughts, once he asked if it hurt while I was doing it and looked genuinely concerned when he was asking it.

He reassured me that it was something that I had learned to do to survive difficult feelings and said that he didn't want to take any coping strategies away from me. I think his thoughts are as I progress through with him, I will find other, more healthy ways of dealing with the difficult thoughts and feelings I have and SI will therefore "naturally" cease. It has reduced a lot over the last 6 months. I also remember him saying that he didn't want to focus on it, as that can lead to an increase in SI - can't remember the exact words he used, but I am sure that is what he meant.

So I guess what I am saying is although for me it is shameful to talk to T about, I am sure it is not an uncommon thing for T's to come across and that your T will know how to support you - IMO their reaction would not be a negative one.