I would not call it a quirk but my T visits the bathroom all the time, sometimes even in the middle of my session. I believe this is probably a medical issue for him and I would never mention it, not something he can change easily I guess.

One that I find funny: he sometimes has a glass of water for patients prepared sitting on the table by the coach. Often the first thing he does when I sit down is that he grabs the glass of water left over from the previous client and tosses it on the potted plant next to it. Initially there was always a fresh glass of water prepared for me when I entered but he does not bother anymore because I never drank from it.

Former T would always come to the door when I enter the room and never sat down before I took my place on the coach. But he was quite slow moving, meaning that often there would be like 30 seconds between me and him sitting down, and I would often start talking immediately. For some reason, that stopped his movement and he would not take his seat if I spoke but remained standing looking down at me. That was moderately annoying and I sometimes asked him to sit down, or there was a minute of awkward silence in the beginning.