Supervisors, consultants, and if they're at an agency other colleagues there.

Typically a therapist builds enough supports so that they can leave "work stuff" at work.

They may come home and mention that it has been a really challenging or rewarding day, but spouses don't really need any other details from that.

T's want to protect your confidentiality, and also want to protect their personal time so that they're not bring work stress into other relationships.