Sorry this is a bit long.
For a number of years I have been concerned about my SILs parenting of her only son. I have never mentioned the matter to her and have instead tried to be supportive. I am not a perfect parent either.
He is now 10 years old and his behaviour is becoming worrying. He screams at his mother, hits his uncles, punches walls, makes spiteful comments and lies incessantly. Last time we were at my MILs he threw two tantrums that were so severe my DS1 his under the kitchen table.
He has also had to move schools due to his behaviour, made racist comments (that horrified my SIL) and struggles to connect with other children. Whilst not his behaviour he is also very overweight to such a point that his mum has to order his clothes online.
To be fair he has moderate level ADHD and a difficult home life, he has recently been abandoned by his father. I do understand that this makes the situation more complicated but he is never disciplined or even corrected. He also plays hours of video games including 18 games such as Call of Duty or Grand Theft Auto. His TV viewing is just as bad with shows like Stranger Things and Rick and Morty.
I don't want to cause problems but his behaviour is escalating. I am worried about him. His behaviour is also upsetting my DC.
I don't know what to do.