This happened to me once with a Mistress I knew well and had see three or four times previously. She only travelled to NYC once a year, which meant I would have to set up a session a week or two in advance.

By the day of my session I was in a dark place personally. I couldn't and didn't want to cancel. I emailed and requested she do something I had never done with anyone before, pretty hardcore stuff. As I got undressed and she prepared in another room, a wave of depression came over me and I was close to tearing up. I said I had to leave, but she saw my distress and insisted I stay. She went back inside to change back into her street clothes, and had me sit next to her on a couch and asked me what was wrong. She hugged and comforted me, listening and providing support.

Oh it was not a session. But it was an overwhelmingly generous and powerful gesture by a very caring person I still consider a friend. I'll never forget it.