I have been seeing my therapist for a couple of years. He was recommended by a friend, who knows him as a friend from childhood/young adult years. They are now both in their late 40s/early 50s, and I am younger. I also know my therapist's parents (though we were never overly close and I don't see them regularly now), from the same context as I know my friend.
As a result I know of, but have never met, my therapist's siblings. I know how many siblings he has, their names, and I know that he's married to someone who's reasonably well known in a particular industry. I have looked at his wife's public Instagram account and there are photos on there of the two of them, and also of their children.
My therapist knows I know the mutual friend, and he knows I know/knew his parents. He doesn't know that I know he's married, that I know who he's married to, or that I know his children's names.
Part of me wants to tell him, but I'm afraid that if I do he'll say that I can't see him anymore because I know too much about him personally and I've looked at social media of his wife and also his brother, where there are more photos, although none of them are recent. I really value him as my therapist and I don't want to have to start over with someone else. Do you think he would have to stop seeing me if I told him?