My husband paid his ex directly, now he’s in arrears

My husband has arrears of payments as he foolishly paid his ex partner direct, even though she was claiming benefits. The money was used to blackmail my partner and I witnessed this, for example she would not let him see his son if he didn’t hand money over. Also the son lived with grandparents for a couple of years and he then gave money to them.

He now has a huge sum to pay, which he is. He payments have suddenly gone up from three hundred pounds a month to eight hundred.

Do my wages get taken into consideration for debts he had over ten years ago?