-What's up with the OW? Is she completely moved out? -Any contact between W and OW still ongoing?
Now to the family camping vacation. I am puzzled as to why you said you were not going. Sometimes it is okay to do this type of events (1 out of 5) because you want to leave a POSITIVE memory of it in W's mind. We read many stories of WASes returning back to the M and the LBS because of their positive memories of some interactions. They do see the contrast between the LBS and the OW/OM.
It's something you want to be aware of during the DB journey.
As for MC counseling, there are three sides to the process.
-WASes who are in active in an affair attend MC so they can check off the box "I've tried everything" while still having the foot out of the door -WASes attend MC sessions to let the LBS down easy and work on a path to divorce -WASes are conflicted and confused so they look to MC as a resource to guild them (BTW, the percentage of WASes going with this third option is quite low)
If your W goes to MC sessions and broaches D talk, then you can state that a D isn't want you want and will not participate in the sessions for she's blowing up a family unilaterally. Also tell the MC outright that W had an affair with the OW. A lot of the times WASes just won't tell the MC the full picture. Don't be the passive party here.
Hope this helps.
FYI, I am very rarely around DB forums over the weekend. Will check in on you next week.