u/Appointment-Empty

I’ve been with this family 12 years and adore the younger brothers (10 and 5), but the 12-year-old has started making racist jokes, mocking disabled people, and doing the whole “edgy middle school humor” thing. He goes to a very wealthy private school, dad is pretty conservative, and mom presents herself as very progressive/liberal, so it’s been strange and disappointing to watch. He’s also very mean to his ten year old brother particularly.
I shut it down every time and make it very clear I don’t find it funny, but it’s gotten to the point where I dread being around him.
I feel guilty even saying that because I helped raise him since he was born, but I’m struggling. Has anyone dealt with this stage before? Did it pass or did it change how you felt about the job long-term?