First of all. Take a deep breath and don't panic. You have time to decide what to do.
Here are some general things all people will agree on:
1. Perhaps the reason your W is having an affair, may have something to do with a mid-life crisis. So, perhaps it has little to do with you.
2. Perhaps the reason your W is having an affair is that your marriage was lackluster or had some serious problems. Addressing your contribution to those problems is key. Doing is better than talking.
3. Begging, pleading and being needy is not helpful -- it will only drive her away.
4. Chasing after her with romantic enthusiam will not work. This smacks of desperation. You chase and she'll run.
5. In some sense you need to find yourself again, regain your personal power and master yourself. Excercize, hobbies, rebilding your social life, are all ways of solidifying your emotinal and spiritual life during a time of free-fall.
6. Being grounded and strong is the best way to attract your spouse back.
There are several schools of thought regarding exposure:
1. Don't expose. This is more in line with Divorce-Busting philosophy. The idea is to detach from the affair, get a life, become attractive again, become less available and less desperate. The idea is that you become the better option and, as your wife eventually loses interest in the OM, she will slowly return to you.
2. Expose. This, sometimes, brings on unintended consequences, but it may bring things to a head in your favor. You need to be prepared for a more dramatic situaton.
2a. Expose only to your wife. Let her know you know. If you do, what's your plan? An ultimatum? Telling her firmly you want to work on the relationship? Begging and pleading for her to stay? If you are not prepared to make an ultimatum and she refuses your plan for reconcilation, then what? You can divorce-bust and try to attract her back by being your best self.
2b. Expose to your wife and OM's wife. This makes it more complex. It might work, it might not. When you actively try to break up their romance, it makes it more delicious and forbidden to them. What if your wife and OM don't give a rat's ass about the exposure and continue to see each other? This makes you look like you are all bark and no bite. Are you prepared to separate, divorce her is she doesn't comply?
2c. Expose to whomever you feel it's appropriate. Make the whole thing appear sordid. It's the scorches earth policy. It's the nuclear option. You fear losing nothing, so you can play hard-ball.
In my situation I wavered between DB-ing and exposure to others.
In retrospect, exposure of OM to his church/wife set him running with his tail between his legs and he dropped my wife like a hot potato and went back to his wife. My wife didn't give an inch and still doesn't have remorse.
General thoughts:
1. If your wife is in the heat of the affair, she's not likely to experience remorse.
2. You must master yourself.
Questions:
1. Do you have children? 2. Who holds the purse strings in the family? 3. Did you see this coming? What were your problems in the marriage
I think exposure to wife will happen sooner or later. Perhaps sonner is better. But, on the other hand, can you live with your wife not breaking it off with OM? Are you prepared to make an ultimatum?