This hits close to home. My therapist has done this for me although I wouldn't call them "secret sessions". Late last year he started putting up more boundaries around email and support outside of sessions and it has been really difficult for me. He's on a vacation now and he gave me a whole speech about his family and others calling him out for working on his vacations and he's bad at boundaries. He pointed out that I've never asked for any of this (I needed it though), that it was always his idea because of his anxiety or people pleasing. Somehow he still made me feel guilty about all of our past vacation sessions.

So basically we're not having a session while he's gone. I was actually fine without a session, but this speech really hurt my feelings. He offered to send me an email message while he was away. I told him if he's going to have boundaries he should just have all the boundaries. Finally I told him I couldn't stop him from emailing me and he laughed and said "no you can't", so he emailed me.