This is indeed a problem.
But unless, they are REALLY NEEDED/Teamwork or fear retaliating
Simply slowly but surely distance yourself. Even if you need to pull out BS excuses.
Also,
the big point is : the mentality
just think : they are ----
to feel less bad ab it
but its what they have against you to profit from you.
Offending, considering that I give high grades because I want to help, not discourage kids.