I've had some close calls, mentally ready to just "let go" and then clenching down, stopping myself, because I'm not diapered LOL. This happens when I've worn a lot for awhile (say, over the course of a weekend) and then I change and get ready for work.
Of course, I do leak when I laugh or sneeze, and that isn't something I can control. If its particularly frequent, I wear Rearz cloth trainers in the evenings when I'm not diapered up. Lately its been better, but last month it was damn near every night.