Reaffirm that God's grace and power are available for all who turn to God for help. Reaffirm your love for the sex addict. You may need to ask God to give you true compassion for one who has disappointed you and may have done things you cannot fathom. Confront and intervene as necessary. If the person continues to act out in sexually sinful and dangerous ways, confront him.
Most addicts become consummate liars.
They've learned to lie convincingly to maintain their double life. Don't trust everything they say. If a person has not begun treatment, make the goal for him to take that step. This is done similarly to interventions for alcoholics. Care for the addict's family, especially the spouse.