What is condonation of adultery?

Condonation is approval of certain behavior. If someone does not object to something, courts held that the person approved of it. As it applies to the divorce, condonation happens when they resume sexual relations after one learns that the other has been unfaithful.

A night together for old time’s sake after learning of adultery pulls the legs out from a case based on adultery.

Black’s Law Dictionary states that to use condonation in a divorce case means that it "must be free, voluntary, and not induced by duress or fraud... This defense had been abolished in those jurisdictions which recognize ’no-fault’ divorce."