We've just adopted a 12 year old. He's from within DP's extended family so he knows him very well.
He's been with us a week and we've both noticed the toilet now smells because he pees with abandon and it's all over the seat.
I said to DP he must mention it and he recoiled and said he feels too embarrassed and doesn't know how to. He finds this sort of thing v. difficult, also struggles with expressing emotion etc. I would just say, oi, X, I'm sick of wiping the toilet, please be more careful when you pee. And leave the seat down while you're at it. Job done.
BUT I don't really want to say anything because I see it as DP's job because he's a man and because he knows him much better than me.
There will be lots more hygiene issues coming up, so I'd really like some advice from other parents on how to handle stuff of this nature...