Read what Michele says about affair. I am quite sure it must be severed
- no contact to reconcile/restore the marriage.
Of course, you have no control over H, but your changes can trigger his changes.
(Re-read DB/DR - you are in the best place now to use these techniques for the best results.)
For me no-contact is the only answer. As relationship is an evolution of a friendship.
Boundaries were ignored or non-existant and thus the A.

Boundaries are a challenge (for me).
No-contact would be a primary for me, but that is me - fully realizing I can't control OW attempts
but expecting H to not respond (being too "friendly" was the problem!).

Ignore OW to the point that she is so insignificant she eventually disappears,
which is how I deal with OW - I will not obsess and I will not bring OW into
our M in conversation, thought, etc
(in any addiction the challenge is to keep addiction out of addict's thoughts).
Also, don't concern yourself if he is lying about OW - concentrate today on laying out your future w/H.
Stay focused on (maybe re-write) your goals.

It is significant to know if you are dealing w/MLC or A or both.
Educate yourself on the life cycle of MLC and/or A. Plenty of info on this BB and Jim Conway's site.

I posted information on thread
"What does it look like when they turn?"
http://www.divorcebusting.com/ubbthreads/showflat.php?Cat=&Board=UBB34&Number=326836&page=&view=&sb=&o=&fpart=6&vc=1
go to p.6 - post #10 by LoveSuffersLong
it is right underneath a big blue troll - can't miss it.
LSL