I hope Dan never tries convincing the kids that they are in a broken family because it was their mother that pushed through the divorce. If such a situation were to occur, it is time to contact some of Dan's mentors (ie Nathan) to intervene.
Kerry, if he tries ANYTHING from this point on that is manipulative/underhanded, I will be contacting Nathan, Dan's parents, his sisters, whoever. Someone needs to save him from himself and I KNOW FIL will not tolerate him screwing me over after what he has already done to me.