I have been recording my sessions for many months, and no my therapist doesn't know. I keep the recordings in an app that is 'locked' with a code on my phone and I don't publish them anywhere or share them with anyone - they are only for me. I dissociate a lot in therapy, so going back and listening to them helps me to pick up on things I missed during the session and listening to my T's voice helps me to stay connected to her as well. I do not feel bad for recording the sessions. If I was publishing the recordings somewhere or sharing them with someone else, then I would feel she should know - but for my own personal use I feel that it is fine.