I am sorry that you're reeling at the moment. As with any negative emotion, this shall pass.
From what I've read around here and heard in IRL, a lot of the marriages where there was an A that preceded the wedding, they typically don't last because the shine has worn off and hard, cold reality has set in with the affair partners. Because they did not work on their respective issues before jumping into the next R or they're far too broken to sustain a strong loving and supportive R.
From what you write here, I'd be very surprised to hear that J and OW will go to the distance. If they do, it will be a miserable marriage all around.
Don't give them the head space rent free.
It is good to go back to IC and work through this issue to bring yourself some peace about the whole crazy situation.
