One day when I was around 10 or so my stepfather came to my psychologist's office, so she took him in to chat. She started off with hellos and then said, "Now, your daughter -"
To which my stepfather, the only daddy I had (because my bio father had "better" kids and didn't care, btw), interrupted her with an ugly laugh and corrected, "Oh, she's not MY daughter".
In front of me.
This therapist was not good, and she caused more harm to me in the long run, but her jaw dropped when she heard this and sent me outside to talk with him alone. Damage was done, though.