Objecting to the other spouse's request for divorce is itself an irreconcilable difference that would justify the divorce. A spouse can prevent a fault divorce, however, by convincing the court that he or she is not at fault. If the only no fault divorce available in a state requires that the couple separate for a long time and the couple doesn't want to wait, they might pretend that one of them was at fault in order to manufacture a ground for divorce. This is collusion because they are cooperating in order to mislead the judge. If, before the divorce, one spouse no longer wants a divorce, he could raise the collusion as a defense.
Condonation is someone's approval of another's activities.
For example, a wife who does not object to her husband's adultery may be said to condone it. If the wife sues her husband for divorce, claiming he has committed adultery, the husband may argue as a defense that she condoned his behavior. Connivance is the setting up of a situation so that the other person commits a wrongdoing. For example, a wife who invites her husband's lover to the house and then leaves for the weekend may be said to have connived his adultery. Provocation is the inciting of another to do a certain act.