Joe...so like Deja in my first marriage, my W had an affair which brought about our divorce. At that time for me, I was of the mindset once someone cheats, that marriage is done, divorce and find someone else. It was black and white, the thought of recon was never a thought for me. Well now in my current sitch i haven't the foggiest clue what my WW is up to. She may or may not have an OM. Thing is when she left I was way more interested in R'ing with her...again likely because i have no evidence of an affair/OM. As time has gone on, i've spent a good bit of time asking myself "if W did have an OM and someday wanted to come back, what would i do?" Along those lines i've spent a great deal of time reading up on how incredibly hard R'ing from infidelity can be and at least right now...I'm thankful I do not have to make that decision. I still believe for me it would be a yes/no moral question. Did she cheat with OM? if so, then I can't R with her. Thing is I KNOW I would be an agonized, completely angry hot mess as I would know that i loved her, never wanted us to be in this position and would be raging against having to make such a painful decision especially as if I had said yes, then my D might have her family back together again. It is true to me that the R we all desire is infinitely harder to deal with if/when the chance of it comes around.
What I want to share with you from what reading i've done on the topic is that the concensus seems to be that it takes the betrayed spouse between 2-5 years to "recover" from the betrayal. If you look at what Sandi says about WWs and how long they need to process through whatever they are going to, that timeline is similiar. I think what I would say to you is that you are WAY early days both in any kind of R AND in your recovery process. I think you need to do your best to let this unfold naturally and not make rash decisions. Perhaps set yourself a marker of say "i'll give it 6 months" or something like that. For me given what I know of your sitch, I'd be a flat no even though as I say I would HATE it.
As for the OM, she needs to fully terminate contact with him. It is noble of her to be worried for his child, but that is a leverage point for him in her life and it must be ended. Definitely something that could be spoken about in MC. She needs to focus solely on the family she betrayed and not any other. Just my two cents.
praying for you buddy...give yourself the grace of some time to see where this goes before making final decisions.