As a school principal, I relatively quickly learned that leadership can be challenged by mateship. I always tried to allow respect and professional regard to transcend friendship and personal feelings about the people I worked with.
In the same way, I would advocate very strongly that teachers teaching children in classrooms should not allow friendships with parents of children to get in the way of their professional responsibility to board teaching tasks. Sometimes, It cannot be easy to need teachers to counsel parents about a child. I made it more difficult by “friendship” with the parents. The difficulty can be not wanting to offend the parent by telling things as if they offer home truths.
The onus is upon teachers to separate their professional and personal lives from each other. Allowing a personal relationship to cloud professional responsibilities can have disastrous long-term consequences.
If there is any chance that a conflict might occur, it would be wise policy for teachers to discuss matters with their senior or school principal.