My mother is appalled by this. It came about when DD4 (15) came home in a mood about something at school, I was on the phone with my mother and sister. She said "Mr X said we cant use Y room at lunch any more for health and safety, which is bullshit, he just can't be arsed being in there".
I made sympathetic noises, she went up to her room.
Mother is disgusted that I "allow" this. DD has no younger siblings, and all her older siblings were allowed the same as long as they didnt do it in front of their not-at-senior-school younger sibs.
I just think that they are all swearing like dockers at school so what is the point in pretending they dont? I swear a lot, especially when driving, so it would be very hypocritical of me to censor her. Obviously, she knows where and when it s appropriate and never swears in front of her Grandma.