You have to pick your battles. If I sense a confrontation, I always listen
to the grieveance then end up asking "What do you think is fair? How can I
help?" Throwing the ball into the opponent's court usually extracts a
compromise. If I can live with it (and I usually can), I let it go. I
always thank the parents for helping me to find a way to deal with the
problem. I look like a hero, and the parents think I'm fair.
The other thing to remember is that all the kids who are doing well are
going to love/like you and those who don't do well will think you weren't
very good(think bcak on your own life as a student). It seems directly
proportional, but if you treat all of them fairly, even the duds will cut
you some slack.