In my experience, therapists have heard just about everything and aren’t particularly moved by sex talk. Over many years, I’ve shared extremely explicit sexual details with my therapist and noticed that any discomfort usually came from my side. I can imagine that for her it was a nice break from a lot of the depressing topics she listened to throughout the day. It was certainly more comfortable than talking about ‘our relationship’ which was our mutual pain point.

I have little personal experience with BDSM but it’s an area I am naturally interested in it and would have little issue listening to someone share whatever they felt comfortably sharing.