I am actually friends with my former therapist. I had to change insurance because the one I was using was no longer offered on the marketplace. Couldn't see her anymore. She let me continue seeing her for like 1/4 her normal rate for a few months until I could get into a different doctor. Now we text, chat, and see each other at pride (she is a 65+ straight, cis, married woman in southern US). If I'm going to be in the city where she's at, we'll occasionally get lunch or something. She's awesome.
Oddly enough, though, I think that level of friendliness messed with the actual therapy. Love her to death, but we did more chit chatting than actually delving into anything, and I got so fond of her that I began to get embarrassed sharing anything that I wouldn't already share with friends/family.