For me, it is not that the therapist is not just another human. I have dated people who were therapists. But it is like I would be with any other professional acquaintance. I would not (there is nothing wrong in my opinion if a person chooses to do so - just I would not) go up to the dentist or the accountant or anyone else I did not know in a social setting. I prefer clients and students not come over to me in non- work related social situations usually.