Dazed,
I am a complete pesimist when it comes to this, but there is something going on with your wife and the OM. It is clearly an EA at minimum, there are so many red flags, warning signs, danger Will Robinson danger, in your post.
Do you really think her meeting the OM was only as friends. I call BS, their plan was to consumate the affair in the physical.
I would contact the OMW and ask her what she knows at some point, but not until you get more intel.
I am pro-exposure and pro-tough love.
You need to gather intel, do not expose until you have all your ducks in a row. When you are ready to expose, DO NOT reveal your sources no matter what, just reveal that you "know everything". Puppy, Gucci, Robx, others are experts on exposure.
It has been said several times here, but cheaters will lie and continue to lie. My STBX still lies about her affair.

Read up on boundaries. Get yourself dettached.

The biggest mistake I made was rush the exposure, and in hindsight I should have lawyered up immediately.
This is only my perspective, others do not agree with the tough love approach.
It sure appears that the success rate with a WAW is very, very low, especially with an EA.
Good luck, my prayers are with you.
Dane