It is also a matter of how the OW behaved during the A period. Let me explain : the OW in my case, after o nly 2 months A she was already sending him emails saying "baby, why cant we BE together as a normal couple", when she saw him going back and forth she kept reminding him how dead our love was and how coming back to me was the biggest mistake of his life, when at one point she realised (1 year in the A) he wanted to try with me she went ballistic threatening him to tell me about and then analysed how staying for the kids would be a mistake cause the kids would eventually move away and he would be stuck with a woman he didnt love (our kids were 4 and 5 yrs old).
I found tons of emails where she kept talking about their past together he was about to throw away, how people wont change and then saying she would change all the things he didnt like about her... Pathetic and no self respect. Sadly my stbxh bought all that form her till recently. She ven used the guilt trip card about her abandoning the idea of having a kid (after an abortion they had) since she is 36yrs old and how that didnt compare with what he was missing out since he had 2 kids (he obviously said he was paying a high price to be with her).
If he ends up with her, I will never accept her as my kid's step mom. (she promised she would love them as if they were her own, GRRRR) K