Under the clean hands doctrine, a person who has acted wrongly, either morally or legally - that is, who has 'unclean hands' - will not be helped by a court when complaining about the actions of someone else.
Unclean hands can be used as an affirmative defense in cases where the complaint is equitable.
In family law, the doctrine is invoked most often in two situations. First, a parent who kidnaps and then later requests custody will often be denied custody unless the child is in danger of harm from the other parent. Second, a spouse who conceals assets or otherwise misappropriates marital property during the marriage or separation will often be penalized in the division of property at the divorce by being awarded less than her fair share. This, of course, requires that the innocent spouse learn of the concealment or misappropriation.