I'm in therapy because I need help, and so it's T's job to help me. If something came up between sessions that was so catastrophic that I felt I needed his help, I would call. Well, maybe. I'm not very good at asking for help.
I don't need any help with the good stuff, so that waits until session. But sometimes I wish I could call him like a friend and just blurt out the good news.
Hell, if I didn't have some boundaries myself, I'd talk to him every day .....

No reason needed ....