Two of my Ts have teared up in session. Neither of them have actually cried full out. School T used to do it kinda frequently because she was even more inexperienced and had a very hard time hearing about what I was saying. I'd handle the situation by saying "you look really upset". This would usually make her snap back and collect herself and acknowledge that she was feeling very empathetic.

LCM has teared up I think a few times but the one time that I remember very clearly because it was unexpected was when I told her (while still residential) that when she comes to work in the morning, I feel like a little girl whose mom has just returned home from work and I want to run up and give her a hug and tell her that I missed her but then I remember I can't do that because I'm not her daughter and I will never have that experience. She teared up and it threw me off a little because I'm somewhat prepared for an emotional reaction when I talk about trauma or something.