You DO owe him the m oney....so the "right" this is to pay it. I will be constant fighting about it until you do.
You can't control his drinking, anyway. You can't protect him from the natural consequences of his drinking. What he does with the money is his decision and it is on him.
I know you would love to control his drinking in some way in order to hang on to the relationship. But....you didn't cause it; you can't fix it; and, you can't control it.
This is likely as good as it is going to get.
dandylion