This is coming from a "control things that have to do with me freak" and I don't think it is not good to be in control of one's time or self- but I think it is like you are trying to control the therapist too here - again, I am not saying controlling the time is not a good thing to do - I believe it is. I completely control the time with the therapist I see - I get up and leave as soon as the time is up. The woman told me to go over once and it freaked me out so badly I managed for about 5 minutes and then stood up and left. I did not want her to tell me when the extra time was up in a surprise fashion. - Same act, but sounds to me like different motives, because here it also seems kind of to be about him too. Like you don't trust him to know or mean his own boundaries. (I could be completely wrong) - in your fear to not be the sort you don't like, you are still disregarding the other person in a way.

What worked for me was setting a specific time on the over time - 5 minutes or 10 or whatever so I knew and it was not a surprise or her whim to add on or cut off without me knowing.