Blouise
I wish I had the answers for you.
Maybe living with the grandparents might be an alternative. But they’re not there to fund his addiction and he needs to realise this. I’m not sure they would be strong enough to say no to him, definitely not giving him cash.
I would seek some advice on this, I would worry about putting my son out at that age. He gave us a hard time at that age, but fortunately he still managed to hold down his job.
It was very stressful, he spent his wages as soon as he got it then continued borrowing until next payday.
Try speaking to him, and give him conditions and boundaries maybe? If you’re struggling with his demands, I think it would be difficult for the grandparents to deal with.
Be strong and be firm with him.
Otherwise he walk all over you.
Take care
Lx