The only thing that stopped me from telling OW's H is their kids. I didn't want to be the cause of their broken home.
Its bad enough I know the OW, but to have pictures? Oh dear.
nepharti, I think your gut is right. If its not physical, its an emotional attachment, don't you think? Oh and I have done the apology thing for sure. But these days I will only apologize for what I have done in our marriage to get us to this spot, and will make clear that I will never apologize nor accept responsibility for his A.