A spouse may feel like he or she is responsible for his or her spouse's debts. This is not true.
A person is, of course, responsible for his or her own debts. In addition, that person may be responsible for his or her spouse's debts under certain circumstances. If you and your spouse have co-signed a debt together, this may be a debt that the two of you share. For instance, if you have bought a car together, you may both have signed for the loan.
If you live in a community property state (Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, or Wisconsin or have opted in to community property arrangements in Alaska), you and your spouse are jointly responsible for debts either or both of you incurred during your marriage, even if you did not "co-sign" for them.
You must be legally married to file a joint bankruptcy petition. Although it is not yet settled law, in states in which gay marriage is legal, a married gay couple may also jointly file for bankruptcy.