Yeah I've been there too. Not sharing personal info, pictures, or actual phone calls, but sometimes random flirty texts in between sessions.
Then when the mpas left the business total radio silence, as if I never existed. I would send a goodbye text thanking them for the good times and expressing best wishes for the future, but never a reply.
So now I consider that the norm when they leave the business, but I still send the "goodbye, thanks, and good luck" text as I think it's the right thing to do, and in a way it gives me closure regarding whatever fondness I felt for the lady.