Wow! Thank you to all who have taken the time to read my ramblings and especially those who took the time to reply.
Some of your posts have been so spot on, it's like you are seeing inside my head.
Ok, so a couple of clarifications.
How C-day works. Basically it's a commitment made in "good faith", where, what we are saying is that all things being equal, we either continue on the R path, or not. It is not binding, and is really an opportunity for WW to show her commitment to the process, and then for me to set the terms (ie. length of time I'm prepared to continue). My declining to commit does not trigger any further actions (indeed, I have declined to commit in the earlier phase during the day-by-day period), and it gives everyone a clearer picture of where things are at.
Secondly, DD. DD occurred during the second major COVID lockdown. We were only allowed to leave the home for 2 hours per day etc etc and WFH was the order of the day. Following disclosure, WW moved out of our bedroom (at my insistence) to our Caravan (travel trailer) while I processed everything. My feelings towards her IC are indeed complicated. In one sense I'm grateful that IC was able to help WW through her depression and other issues to help her on a path towards becoming healthier, but on the other hand, I can't help but also see her as a co-conspirator? (does that make sense?) I mean that IC had no dog in the fight, had WW decided she wanted AP, IC would have likely supported that position too - so I am keenly aware that IC is in no way on "my side" in this. Initially, during lockdown, an attempt at R seemed the logical choice at the time - given neither of us were going anywhere. I get the idea of control some of you have raised - it has occurred to me as well, however it is something that the MC is keenly aware of, and MC works very hard to give me agency in the sessions and the overall direction of the MC and R more generally.
Now the sex thing. Please be aware that I'm not completely comfortable with typing this - so if I write the wrong thing, or provide too much information, I apologise in advance. So regarding the sex between WW and AP, I have all the details I could want, including locations, dates and sex acts performed. I also have another document that I have not yet been able to read which contains more detailed descriptions of what occurred. I know that one day, I will either read that document, or delete it - but I don't see that day happening soon.
So vanilla sex between WW and I basically consists of Missionary PIV only, with WW adopting a passive role. Lights off, in bed, quietly so teenagers do not hear. Exploration of new positions, OS (giving or receiving) or any other things many other couples consider routine have never been part of our bedroom activities. Curiously, WW maintains that she has never had an issue climaxing with me, and "doesn't wanna mess with what works".
On the other hand, the PA was initiated with WW providing OS to AP, with it being reciprocated shortly afterwards. From what I can tell, the physical side of the A consisted of "pushing WW boundaries" and "opening her sexual horizons", as she was inexperienced as I was her first. Her AP seemed to get off on the idea of introducing WW to the new things, to rack up as many "firsts" as possible. (god that's painful to think about/type). WW was an active participant. Their bedroom was a whirlwind, whereas ours has been a light breeze at best.
I have a huge amount of resentment that at least some of the refusals that I experienced from WW during the A were at the urging of AP. He didn't like the idea of her being with me and not him. OBS confirmed that AP has a jealous streak. I still get angry that WW was denying me to "be faithful" to her AP - omfg - the hypocrisy!!
So yes - I am considering ending it over the sex thing. It eats me up inside, and twists my thoughts. I struggle to enjoy the things with WW as those mind movies play uninvited in my mind at the most inopportune times. I worry about if I am shallow to end it over the sex, but that is kinda where I'm coming to I think.
My relationship with the OBS is another thing. Has anyone else experienced an irrationally strong bond with the OBS following an A? I don't mean physical, or necessarily romantic in nature, but the pull I feel towards the OBS in all this has been surprising. I find I must be mindful of my boundaries during my interactions with OBS. They too are working on an R, but it seems to be going rockier than ours. AP has experienced some health issues (unrelated to A), and has developed ED as part of it (my heart bleeds!).
So yeah - that's where I'm at. Is this as good as it gets? (maybe?), Am I ok with vanilla only going forward (no... not at all). Even with WW going above and beyond in everything else - is it enough? (maybe, maybe not?). I could describe my thoughts on our future in one word at the moment "blah".
So thank you those who have read through my second tome, the feedback is really helpful. I don't feel so shallow and self centred considering leaving the marriage, despite WW good works.
Cheers.