I haven't cut for about 2 months now (which by the way, is amazing for me).
I have been seeing my t for 4 years. She knows that I have cut, and that it's possible that I could again.
When I cut, I feel awful because I know that I am going to have to go talk to t about it.
In my opinion, it is really important to be able to tell your t about what's going on, even when it includes cutting. It's going to be awfully hard to get better and do the work you need to in therapy if you can't talk about something as major as cutting.