AIBU - old friend sleeping with my ex

[itsmellslikepopcarn]

What are your thoughts on this?

Some back info - with ex for 8 years, engaged albeit briefly and have DD together. separated for 2.5 years, after the women he left me for broke up with him he immediately started spending a lot of time with an old friend of ours.

I haven’t spent proper time with the girl since having DD but we would see each other at birthday parties etc, and spoke every couple of weeks online. I’d say about 10 years ago she was my best friend, she used to model for my business, we would go out together regularly and spoke everyday.

I’ve cut her off completely now because I think it’s a line you do not cross. I wouldn’t dream of sleeping and getting into a relationship with her ex who is a mutual friend of ours, but neither ex or old friend think they have done anything wrong. AIBU to think she has crossed a line?

I don’t understand the ‘cool girl’ vibes. This is her ex. That is her friend. This woman might have known him longer but OP met them both simultaneously. But here’s the kicker, they have a child together. It would be a bit of a shit thing for a friend to do if they didn’t, but as they have a daughter together, the OP is very not being unreasonable to be upset by it. Especially as they both defensively hid it.

YANBU at all, there’s a definite line people shouldn’t cross and she has. May be different if this was an ex you weren’t with for very long but you have a child together so your lives will always be enmeshed.

OP = "Probably because my ex isn’t like that, he was violent, was abusive (all of which she knows and excused because of his upbringing), cheated, isn’t a great dad and puts his work constantly before his kid, so she has completely disregarded our friendship even if we weren’t close, to be with someone like that.

And his “sexual prowess” isn’t anything to write home about either"

So, you are now changing your objection?

Now you are saying it's not because he's your ex?

It's because he's a poor partner and you want to choose her partner?

I don't think they've done anything wrong. Your friendship had fizzled out. If she was a current close friend that would definitely be crossing a line.

This said I know it's horrible. The same thing happened to me and it's a really unpleasant feeling.

I can understand you’re upset, but…

1. He was friends with her before he met you.
2. You split up 2.5 years ago.
3. You haven’t hung out with her for around 10 years.

I voted YABU but I would be upset too.

Not sure why you are so upset if he treated you so badly, just leave them to it. Men like that don't change.

I can imagine it would be hard but you might find it easier to look at it from the perspective that when your daughter spends time with her dad she is also likely to be with someone you apparently used to like and this friend will hopefully then take better care of her.
My boyfriend cheated on me when I was young. But the woman he cheated with ended up becoming his wife and they are still together 30 plus years later. It makes me feel so much better knowing that - it didn't work out between you and your ex but surely you want him to be happy? Isn't that best for your daughter?