I agree with Doing. I know there are many here who don't support exposing the affair to people who can influence your W, but like Doing, I exposed my W's affair to the OMW and certain close friends.
If you choose that route, do not expose for the purpose of punishing her, it is only to break up the affair. And if you do it, expect her to be ANGRY! She will say things you won't believe. She was going to give you a chance, but not now, not if you were the last person on earth, etc. It WILL be ugly and you can't react to her anger.
Exposing MAY also end your marriage for good, so if you choose to do it, be prepared that it may end your marriage. I only exposed after I got to the point where my W had checked out of the marriage and was going away every other weekend to see OM. The other week OM was coming to our town to see her. I was ready for my marriage to either be over or for the exposure to work to end the affair. And for me, it seemed to work. In my sitch, I knew OM was a player, suspected he was a serial cheater and was just using my W. And sure as heck, as soon as OMW found out, OM cut tail and ran back to his wife. It's taken a while (exposure was 11/13) and my W finally seems to be responding to me and giving some indications that we'll work out (the point of that is that it will still take a while for your wife to come out of the affair fog/addiction to OM), but again, you have to be prepared that exposure may end your marriage.
Some people here call exposure controlling. I don't feel that way. I call exposure shining light on an immoral act. Sometimes that light will make the affair partners come out of their fantasy/addiction. Sometimes not. If she's cake eating (which it seems she is), exposure just might do the trick.
Like Doing says, your marriage will not survive with a 3rd person in it, and you shouldn't have to sit by while your wife trashes everything you believe in. With exposure you must be prepared to go on with your life, with or without her.
Just my $.02
Hope4us
Me - 49, W 49 S22 & S18 Dday 9/4/07 W claims NC 4/7/08 8/29/09 - Divorce Busted. Lots to work through, but we're going to make it.