United States done that
In other languages. My mexican friends and I liked to talk sh*t about our 6th grade science teacher in spanish and she'd never know.
Philippines nnnever
i have cursed, not exactly in front of her, but she heard it. i cursed in japanese and never knew she was teaching japanese
United Kingdom nnnever
I'm quite convinced your teacher here was abusive in his/her years of might have wanted to report her to the authorities.