Disclose the affair to ONE very respected authority who he is likely to look up to and listen to... someone who is likely to be pro-marriage and to tell him that he should end the affair and work on the issues in your marriage. This person could be one of his parents, a religious leader, a teacher, or a boss. Meet with this person in confidence and explain to them that you expect them to keep the matter confidential, but that you need help. Then explain that your spouse is having an affair and give them the facts. If you can, show them the evidence. Then ask the respected person to help you and support you as you talk to your husband and again ask them to stop the affair.
Step 4. Exposure
Expose the affair to those who will likely be affected by a potential divorce. The idea behind exposure is not to drag your your husband's name and reputation through the mud, but rather to refuse to keep the affair a "secret" and to bring the ugly truth of the unfaithfulness to the light of day. In his mind he may be thinking something like, "Oh yes we might be disrupting four people's lives, but don't I deserve some happiness too?" What he doesn't realize is that a divorce will not affect four people—it will be a like the ever-widening wake of a nuclear bomb, affecting possibly hundreds of people! For this step though, there should be a focus to the exposure. Contact your own family (parents and siblings), his parents and siblings, his church or place of worship, your co-workers, some of his co-workers, your employer, his co-workers, and the other woman's spouse and inform them of the affair, that it is serious, that your marriage is in trouble, and ask for help. Nothing ends an affair faster than the other woman's spouse screaming and putting their foot down. Infidelity: Are Lawsuits The Best Revenge?
Step 5. Carrot & Stick