It's a joint line of credit, so the creditor won't care who took the money - they can attempt to get it back from either of you.
You may be able to get a greater portion of the debt assigned to him throught he divorce proceedings. If at all possible, you should try to separate the debt at the conclusion of the divorce, such that there is no longer any joint debt.
If you go on a spending spree with joint credit to get things for your new household, you should expect the court to make you responsible for that portion of the debt.

