Whether or not the creditor will pursue you, I cannot say. What I can say is that it is certainly a possiblity. A co-signer to an obligation is generally liable as the original maker. If payments are not being made, the creditor generally has the right (and will exercise the right) to pursue all parties liable for the debt. If your ex does not pay the obligation, it would not be surprising if the creditor looked to you to try to collect the debt. You may or may not retain some ability to pursue your ex under the terms of your divorce decree.
The only real advice I can offer is to speak with an experienced family law and/or collections/bankruptcy attorney in your locale to explore all of your rights and obligations in this situation.