I've had 3 long-term therapists and have stayed in touch with all of them for decades now. I'd say we're sort of old friends now that just lightly keep in touch. I facebook with all of them now that facebook is a thing. Before that, we emailed or just spoke on the phone occasionally.

We've been able to do that because I had absolutely no expectation of therapy with them. You have to be able to change that dynamic I think because if you still expect them to listen to you like a therapist, that isn't generally a reasonable expectation.

I've seen them all in person a few times over the years. We've had lunch or were at a function together just coincidentally. My last therapist I run into more regularly since we live in the same town and shop in the same places. We generally just greet each other with a quick hug, chat for a few minutes, and move on with our own business.