It's ok to say no.
There doesn't seem to be much point to coding him, in all honestly. It would only prolong how long you are held hostage to his choices. This is not a statement of the value of life, but rather a practical statement.
You do not have to shoulder the guilt of the results of his choices. To choose to let the natural consequences play out in a manner that doesn't drag you down is not wrong, or selfish.
CLMI