Unfortunately @Changerofthename1 I thoroughly dislike your whole attitude towards this. You do seem to be getting pleasure out of the attention he is paying to you, and I also have the impression that you enjoy having this (potential/power) over not just your ex, but his present partner, and their poor children.
However, in my opinion, your by far worst trait is that you don't actually care whether his children with the other woman get hurt in the process of anything you might say or do to cause your ex pain. In a reply to a PP you said 'that is the dilema', but NO it isn't, there is no dilema there. It is extremely sad that your DC had to go through such a painful experience (and that they may always bear some level of disquiet over it); but how that makes you think that because your children have had to suffer it makes it OK for ANY other child to have to suffer the same thing, is totally inexplicable to me.
Of course I love my own DC and DGC more than any other child, but that does not mean that I can bear the thought of any other child suffering - if I had it in my power to stop any child from suffering, then I would do it. If I knew that an action of mine would cause another child to suffer, without it having any bad effects on my own children, then I still wouldn't do it, surely no right minded adult would?
A real dilema would be if I knew that one child had to be hurt, either mine to a certain extent, or another child to an even worse extent, that to me would be a dilema, and one that I couldn't answer here, as there would be too many variables to take into account - my hoped for answer would be that I could take the pain so that neither child had to. If you even acknowledge my post OP, I won't be surprised if you cannot understand my opinions on this at all.