How to, who to, why, and benefits of exposure etc.
How: All at once, without ANY warning. Exposure should be one fell swoop, not in dribs and drabs. It is a "shock and awe" strategy. No warning, because the wayward spouse knows exposure is imminent, he/she can tell close friends and relatives "My spouse is driving me nuts! They are so jealous and possessive and needy... they're even accusing me of having an affair. I don't know how much longer I can live with this." Then when the exposure happens, nobody will believe it. It will only strengthen the "poor suffering me" story the wayward spouse is telling.
Who to: The people who have influence over the affair partners. This is *always* the affair partner's spouse, the parents of both affair partners, and the parents of the betrayed spouse. It frequently also includes adult children of the wayward, employers of the affair partners if they work together, and members of any "club" to which the affair partners belong.
Why: Affairs thrive in secrecy. What seems delicious and "meant to be, dictated by fate" becomes tawdry and embarrassing in the light of day. It's easy for affair partners to tell each other how wonderful it is that they've found their true love and soulmate, but when people they respect are looking at them with that "How could you be so foolish as to rip your family apart?" look, the affair starts to lose its luster.
The affair becomes more difficult to carry out when "all eyes" are on the affair partners.
Frequently one partner will decide that the affair is simply not worth all the hassle.
Exposure is the single most powerful tool there is for ending an affair. There is no guarantee exposure will end the affair immediately, and it's possible it may not end the affair at all, but usually it has a surprisingly strong effect.
What you should say: Exposure is NOT about revenge. It is NOT about saying "He is being horrible and wretched, please hate him for me." It is simply about conveying the truth to influential parties. Exposure should be short, it should be factual rather than emotional, and it should not expect anyone to pick sides. Here's an example: "My H is having an A with OW. While the decision to have the A was completely his, I realize I contributed to the poor state of our M. I'm committed to improving myself and building a strong vibrant M with H. I would greatly appreciate your support for H, myself, and our M as we go through this difficult time."
When you expose to the OP's spouse, you should have hard proof. The OP's spouse sometimes knows something is not right, but sometimes they don't have a clue anything is amiss and they will dismiss the allegations out of hand without concrete evidence such as copies of emails, cellphone bills, photographs, or taped conversations.