I think your T probably assumed you'd go out the back door and never see this person. I don't think they did something inappropriate, if that's the case. But I don't think T's realize how clients can often feel about their private lives and the people close to them -- for a whole variety of different reasons. A wise T would try to keep their private life very private as a general rule, though of course there can be reasons to share things with some clients.

I'm sorry if it was really disconcerting for you. I think that kind of reaction would not be uncommon.