Letter to the other woman

If you could write a letter to the other woman. What would you say? Without being hateful. I’m not trying to threaten her but I want her to know that she is just as much to blame for my hurt as my husband is.

She knowingly and willingly slept with a married man. Then she sent me horrible messages when I found out. As if I had done something to her bc my (soon be) ex husband ended it with her.

I am not a hateful person but it tells you a lot about a person’s character when she willingly does something so hateful to another woman.

Edit- I guess I should have said I’m seeing a therapist and she suggested I write one not to send (unless I feel it’s right) but to maybe help move on and get the words/thoughts out on paper.