Oklahoma allows divorce on no-fault and fault grounds. A no-fault divorce happens when the marriage simply breaks down due to incompatibility; neither spouse did anything to break the marriage contract. However, a petitioner can choose to file on grounds of fault as well, including adultery, impotency, abandonment (for one year), insanity (for five years), extreme cruelty, imprisonment, habitual drunkenness, gross neglect, when the marriage was devised by fraud, when the wife was pregnant by another man at the time of marriage, or when a prior divorce is not recognized by the state.