In that context, I have always appreciated my therapist looking out for me so that I don't start into something we can't possibly get very far into or if we do I am likely to be in bad shape when it is time to end. I don't see that as presumptuous; I see that as part of his job in helping his clients. A therapist who doesn't help a client manage that kind of thing can leave a client feeling emotionally overwhelmed, perhaps unsafe to drive, etc.