You have really had some interesting posts on this thread. I personally wouldn't send the letter because I believe the OP will do everything to pick it apart and find a way to twist it around to their advantage. I hate to back down on what is moral and right however I have learned over the years that there is no point to try to be rational with the irrational...and IMO, if the OP's were rational people, they never would have gotten involved with someone who is married.
I have always found letter writing very cathartic even if I don't send the letter. Somewhere buried in a box, I have letters I wrote 15 years ago to my XH and his OW. They would be interesting to read now. I am not sure why I kept some of them.
I hope your XH's "out of the norm" contact with your D continues. Try not to give too much head space to it...for now just appreciate it for what it is worth.
