Carp - To find fault or complain querulously or unreasonably.
Tempers frayed whenever Sirius was in his mother's presence for too long. She was always on at him, trying to turn him into the perfect Pureblood heir, a dutiful son, her mannequin.
But one night, she went too far. He'd just had enough.
"Why can't you be more like your brother? Now he's a true Black."
"Because I don't want to be him! I don't want to be a Black! I never asked to be born into this family! I – don't – want – to – be – a – Black!"
With that, Sirius was gone, slamming the door behind him. He never went back.