I don’t anymore but I used to, when I was seeing him ten years ago (I left him and then came back). We just talked about it. He still asks occasionally because I’m borderline and it’s part of my history. He asked me once if I would tell him if I was going to. I said of course.
I don’t think I would ever go back to physical self-injury. For one, I’m scared he would terminate over it but more importantly I just don’t feel the need to anymore. I do self-sabotage in many other ways, and it’s a frequent topic of conversation.