Many thanks for your support.
I won't send as there seems little point.mit has helped a lot posting her and getting it off my chest. Maybe that's what I needed to do.
Fo those who are wondering, there has been NC with OW since November, although I have agreed to contact with OC through OWH only, if FWH will explain why he wants to maintain contact. Funnily enough, there has also been NC with OC for 15 months. He has only seen him 12 times in his life and the OC is now 5. He finds it impossible to articulate why he feels he towardsOC other than that he feels responsible for him. This so called responsibility seems to extend to visiting OW at their house and having coffee with her. He gives no financial support, doesn't babysit, play with him or anything like that. As I say, it has stopped completely since NC with OW - funny that.
My resentment stems from that they were in contact behind my back since the ONS and even after DD1 when OC was 2. This continued until DD2 in July last year. I am angry that she forced that illicit relationship with them both behind my back for so long. I know and accept it is over now, but I still hate her, I am still angry with her and still feel that she needs to be told. ( I accept, as you all say) she won't accept any of it, so what's the point?) she is no longer forcing him to go to her home, but she did for 5 years.
Thanks again for help