Only you can answer whether or not you want to "bother" w/ the M.
I can tell you from experience that while I was in an EA, my W did nothing for me...I loved her but wasnt in love w/ her, she was boring, sex was boring, she didn't cook or clean- so I did, and all she did was work all the time...
We were at our end. I could have cared less- b/c I was getting emtional/ego needs met elsewhere.
Once my EA fell apart, W established one and said she was DONE- I have never loved her more. BTW when my EA failed, ALL I WANTED WAS TO FEEL THAT WAY ABOUT MY W...ironic twist...
So, you have several options...if you're done and ready to move on, that's one. If you want to keep the M...
-protest the A to friends and family- and to H -establish your boundaries, and be prepared to walk away...
There are other options- let me make sure I understand- H knows that you know about the A? He admits it?
If not get all the proof you can get and then find people supporting the M.
From my understanding, you cannot successfully DB w/ OP in the pic- except for outshining them...