I am not by any means a DB pro but, have definitely read a ton here and elsewhere. The A (in my WAW's situation too) is a symptom and not the main problem. Trust me, it hurts like hell knowing about it and seeing all that I see but, if OM was gone it wouldn't fix anything. Actually it may make it worse as her depression and such could escalate and push her to run and file.
She knows I know. Everyone knows. She says they are just friends. Nobody is stuoid but, be cautious of doing things that you know will trigger reactions or actions that aren't going to help your goals. Your goal shouldn't be to destroy OM or his marriage. He's just a tool. A weapon. Take it away and there will be another one as again, the A is a symptom.
Remember, it's not that you can't ever discuss the A. Just now isn't the time. I still catch myself saying stuff that made me feel good for 3 seconds but set me back weeks....it's not worth it.
34, xw33 M-10, T-18 2D (8 and 5) Ilybinilwy-1/16 EA/PA- 7/15-present (with my former best friend) Trial apartment-2/16 (also when she considers us separated) W moved out-8/16 W Filed 11/21/16 D final 1/30/17