Do I live with an arsehole?

[Vcal2017]

I don’t know if the language will offend. I’m in a bar having a drink and I rarely drink so who knows?
My son 17 is in his last year of high school. He’s a smart kid. He’s very politically motivated. He’s very active in a high schoolers for Palestine group.
He went out last night until 10.45 with this group despite needing to be on site at school for 9. They count attendance even though he just has study periods and 1 formal class .
He doesn’t understand that I am concerned for his safety at night, or the impact on his schooling. This is a weekly thing. He turns 18 in June.
AIBU: you should be grateful he’s not doing drugs and hanging around a park.
YANBU: his results will impact the rest of his life and it’s a safety issue to be wandering the streets at 10.30 in a Black Flag t shirt.

Don’t see the issue.

Blimey, imagine calling your son an arsehole for standing up for what he deems right. You are aware of the things he could be doing instead right? Drugs. Stealing things. Being abusive to people.
Why do you think he's an arsehole OP?

He’s not an arsehole.
He’s staying out late with his mates on a school night.

He should probably be getting more sleep but as long as he’s getting to school on time and not being disrespectful to you/your home then there’s not a lot you can do.

In that situation I'd be much more worried about who exactly this group are and what their action involves, than whether my son was an arsehole, whilst also been pleased he was taking an interest and wanting to get involved.

On the face of it, and occasional late night for a 17yo doesn't seem so awful, although he should let you know where he is and when he'll be back.

Thank you for your replies. After some sleep
I realise I’m probably the arsehole. It’s tricky because I can’t sleep worrying about his safety and I have to work the next day. I am proud he’s politically engaged and has beliefs. His grades are good. I’m facing the loss of my Dad and my son is growing up too and I’ve come to the conclusion that it’s more about grief, loss and lack of control for me. Something to work on. Thank you and I’ll try to mute the thread.