Toward the Light: I happen to know Anthony Appiah, the NYT ethicist, and after seeing the "wokeness" tilt in his answers, think you are better off if he doesn't answer you.  I suspect he will take the common view of saying that one isn't allowed to "out" a closeted person.  (I disagree on the basic level of speaking the truth about one's own experiences is "outing."  "Outing" I reserve for "trying to harm someone by revealing their hidden sexuality.")  I'd love to see what you wrote, however, and could share with you my own private writing on this dilemma.

And Lily, it is horrid.  I did not think my ex would ever get involved with another woman, but I see I underestimated his perfidy.

Light: I didn't see your message in my inbox.  

I actually don't post much anymore.  I've been on the forum since 2016, and much more active earlier, when I needed it more.  This latest development, though, took me aback--and back to a bad place.

An update:  This morning I made a first step in letting the woman my closeted ex is dating the truth. 

  I composed and sent a letter to a friend who is a close friend to the woman my ex is now involved with.  (This friend knows the truth about my ex, and talked to another mutual friend about feeling the dilemma of knowing the truth, but said she wasn't planning to tell the woman in question, information the mutual friend disclosed to me.)  In the letter I explained that I've always said that I would tell any woman who got involved with my ex the truth, because my ex does is not entitled to decide for himself what a woman needs to know, and that the woman deserves the truth so she can make an informed decision about whether she chooses to pursue a relationship with him.  (I sure wish I'd had this information!)

  I asked my friend to let me know if she could counsel me on how serious the woman is about my ex, and how long they've been dating, so I could tailor my own letter to the woman better.  (Will I simply say "You need to know that [my ex] has a secret sexual life and is hiding both his sexual and gender identities from you.  If you need proof, or want to talk to me about it, please contact me," or will I go into more detail?)

 Now I'll wait and see what response I get, if any, and make the rest of my plans from there. 

Whatever happens, I expect you will feel that you did the right thing.

Thanks, Light.  One step at a time.  First the letter to the new woman/beard.  Then one to my son.  I've already had a preliminary conversation with him to set the stage.  That second step will have to wait a bit as I travel to settle my mother's estate.