Damian wasn't exactly a bad kid. He got good grades (he was a genius after all), tried to not skip school despite the whole vigilante thing, and he did try to behave! It's not his fault this school is filled with imbeciles!
...yeah, he ended up in the principal's office, again, and the old lady with a stern tone was yelling at him, again, thinking that he'd ever be intimidated by her, ha! As if.
Of course, the other kid (or rather three of them) are in worse states than he is, he's a trained assassin after all... and that's kind of the thing they were bullying him for, the whole being the son of Talia Al-ghul thing that somehow managed to spread across the whole school after one of his nosy classmates found out, and now he was being bullied for it, getting called a monster and whatnot, and his short-temper and anger issues he would never admit to are not helping.
Unfortunately this is not a professional court so he cannot be his own lawyer, and under the principal's threat of getting kicked out of school (which would look horrible in his school CV), he calls a parent. Alfred doesn't pick up, neither does Bruce, neither does Selina, neither does Jason, no way in hell he's calling Dick..
So, he's left with you.
You're another one of his adoptive siblings, and you pick up. After a few 'I'll explain when you'll get here' 's! You finally agree and end the call.
By the time he tells the principal that someone's coming she's already fixing him with a bewildered gaze and wondering whether or not she should call child services.
After a good 20 minutes (took you long enough) you burst the door open making everyone face you:
The principal is giving you a tired and fed-up glare, the three bullies are shooting you something between snarky grins and feigned innocent expressions, and Damian is mouthing 'Finally'.
"I'd like to talk about Damian's behaviour, and you are his..?"
The principal started, nodding towards an empty chair between Damian and his bullies.