you know the situation better than anyone here. Going to give a try - I hope others post as well - use all opinions but only you know the true situation and how ur H is.

In most BS cases the full exposure gives the light of reality on fantasy. Not sure H is in fantasy - sounds like like a living he// to me.

hint to MIL - perhaps....but it could isolate you from MIL also. Blood is thicker than water. OTOH - thats the place to start.

Are you sure there is a RA? One response you are going to get is that you are lessening your guilt by projecting another issue where none exists. Be prepared.

Start with parents and IL's - be prepared for some backlash. H will be upset - no doubt about it.

By the same token - ur H may hv checked out and will not care. His perspective is that the M was over months ago during ur A.

You will have to compete with OW during Plan A