I agree with all of the above, except I WOULD expose their affair to the other man's wife. She has a right to know, and shouldn't be the ONLY one (of the 4 affected) who doesn't. Let her have the information, so she can make her own, INFORMED decisions for herself and her family.
Puppy
Unless I'm getting my stories confused, the OM's wife knows - she's the one who called Oblivious and told him.
Greek
Me45 H46 T25 M22 S21 & 19 D13 Separated and filed 8/08 Moved home 11/08