My own WW had a window of shock/regret after initial BD/discovery of her EA. At that point the EA was just that... and was really only in beginning stages-- some flirting and musing "Well, what IF we decided to go out or get together.." For the first few weeks after discovery, things started to improve-- we talked, there were baby steps towards "working on the MR" or "getting to know each other again" along with some distancing from OM (she even apparently told him she needed time to "figure things out with hoosjim") and, then, BAM! Major regression. She went off for a weekend with her bff (who, unbeknownst to me at that time had also befriended OM) and, I am guessing (though i still don't know the details here) reconnected with OM at some event or get-together or bar... pretty sure they even spent the night together in a group hotel room (or worse, it's unclear) At any rate, when she came back, things were clearly different with her, and from that point on the A become more and more involved over a period of weeks, and she was more and more distant, rebellious, WW-like, etc. It would be months before she would make any significant effort to end the A and distance herself from OM and start putting in some work, and close to a full year before she would completely cut the cord and go "all in" on reconciling the MR.
It was a hellish up and down, frequently stuck in limbo, process.
I think what sometimes happens is there is an initial shock of discovery, perhaps some remorse, maybe some steps towards "Trying to fix things", perhaps even half-heartedly honest (though i am sure as often as not they are "box-checking" exercises) but then they remember the pull/excitement of the A and the OM and it is back to square one (or worse). I can't imagine that a WW in that situation would ever just "get over it" in six weeks or less and come back to the MR-- a person just doesn't recover from the starry-eyed, hormone-fueled "love" effect that quickly. It takes time. Typically at least months before the OM is completely "out of their head". That said, i AM very sympathetic to Sandi2's view that if, upon discovery of the affair, the LBH IMMEDIATELY manned up and dropped a bomb of his own "It's over or we're done and your outta here"-- the timeline for "recovery" and movement towards reconcilliation, if possible, would be somewhat to significantly shortened.
H53/W51, R-ing 4/'18
"Do not arouse or awaken love until it so desires"-Sg.of Sg 2:7
"So oftentimes it happens,that we live our lives in chains, & we never even know we have the key"-Eagles III 1:3