I would not expose the A to anyone that does not need to know. That will only incite anger in your W and will work against you. I know you want to do it because it will make you feel better but it will work against you. If OM is M and you have indisputable proof of the A, you could consider exposing it to OM's W but there is risk with that too. Most will advise that the person that does the exposing is likely to loose all chance of reconciling because it will infuriate your S.
Me: 48 y/o W: 47 y/o Together: > 20 yrs BD: Dec '15, then S 2nd BD: Mar '16, then I filed for D April '16: started piecing
