Hi there,,,bless your heart for taking this boy in when life has dealt him such a poor hand of cards.
My suggestion would be to suggest that this boy get a job. I would suggest it as not only something to keep him busy but also as a way in which he can contribute to the household.
I would insist that he give you half and that the other half go into a savings account which could be something he could use towards future accommodations.
Also....perhaps contacting the church to see what they might suggest in terms of helping this boy out may be worthwhile as well.
Good luck and I hope that you will come to some peace with this entire situation.
~ Ivory