I think I have a similar thing. When t says 'time up' I don't jump up, but I do fairly swiftly get up and leave. Part of it is about my not wanting to take up too much time / be annoying. He primes me for it now, though, so I know when we are winding down. He has this distinctive change in his voice that signals that we are in the wind-down and sometimes he will say '5 minutes' or '10 minutes' if it has been an intense session, I guess. Sometimes... I really don't want to leave. I wonder what he would do if I just kind of sat there or tried to keep him talking... Maybe... Maybe I do try and keep him talking a little bit already ;-)