Is it obligatory to pay off debts before giving money to one's father, knowing that the father is financially well-off and would not be pleased with not taking from his son?

As long as the father is not in need and the son is in debt and cannot find what to pay his debt with, it is not permissible for him to give his father and delay paying his debt. Rather, he must appease his father in a way that does not harm himself or his creditors.