Namechanged for this as I feel like a right tit.
Short version. Split up with my ex seven years ago when he hit me in front of our son, who was a toddler at the time. No feelings for him, never tempted to go back.
He met someone else about five years ago and they live together. She has never spoken to me and has maybe said hello twice in the time they have been together, which is not a problem and her choice entirely.
Anyway about two months ago I was at my friend's house and apparently (can't remember this as I had had quite a lot of wine) I sent my ex a text and rang him up. I don't know what I said and my friend doesn't know what I said because she wasn't in the room when I did it. God only knows why I did it in the first place because I have no feelings for this man whatsoever. He is my son's dad. End of. I spent long enough being mentally and verbally abused by him and no way would I ever have him back. I have no logical explanation for what I did or why I did it.
The following day I apologised to my ex (when my friend told me what I had done) and he said not to worry about it. I said that I would apologise to his gf when I saw her, but I haven't seen her since then, other than her being in the car when they drop my little boy off.
It's been playing on my mind since then. I know that she has never liked me (this predates the text and the phone call) and this text/phone call fiasco hasn't exactly made me look great in her eyes. I really don't want to have upset this woman.
So I have written a letter to her to apologise. I am planning to give this to my ex later when he drops our son off, so that he can give it to her when he gets home. I don't want her to think that I am trying to get him back or cause problems in their relationship because I don't want to do that. All I have ever wanted is an amicable relationship for the sake of our son.
AIBU to write to her in this way?