Ex-girlfriend dating a close friend. How would you feel?

[Danology]

Imagine a scenario where you break up with your girlfriend and you still have some kind of feelings for her. your girlfriend now your ex, goes on to have a relationship with your close friend.
this act obv is not immoral cause there are two mature human beings with freedom of choice and this idea seems purely justifiable but can it be wrong? The only factor that may come in their way would be me. what if this act somehow distorts my well-being, not in a way of "oh I'm being offended" but in a sense that whenever I'm spending time with this friend deep down i get this feeling that "i hate him because of that" here "hate" may not be the right word but let's say it doesn't strike me well.

What would the rational decision for me to make here?
And what if my friend knew i had still some feelings for her and he did it anyway because he himself also liked her.
And of course what would do you feel about this scenario?

[sage2021]

I once had a female friend that would always happen to meet whomever I was in a serious relationship with. When she would hear that we broke up, she would always find a way to see him and try to hook up with him. She would use his occupation as a way to start trying to hook him. Even though she knew I still had feelings for the guy. And she thought she was my friend. Not!

[miichellee]

You... Should actually try to delete this feeling of discomfort. Now now, i know you can't just decide to delete a feeling and just do it! You should kinda avoid them, maybe. But know, It's not their problem. The problem is yourse. Everyone is independent.

[Vegasrunner]

Im going to give you some practical advice. Own and remember this feeling. I'm guessing that this "girlfriend" began as a mutual friend inside your friend group, and you guys started out as platonic friends b4 getting serious?

[Nawlins34]

I'd be happy for them, but I'm moving on from both. The friend has made his choice.

That's a choice. I need to focus on myself and my life. Perfect time to break-away.

[boggboss]

That would for me personally end my friendship with said person

[Avicenna]

Smart thing to do is talk to other women and forget her

[Shamalien]

Eh…why are girls like this…. do they get off on this drama?

yes. Yes they get a sick pleasure from it

[Anonymous]

The right thing for him to do would have been to ask 1st

[KrakenAttackin]

That royally sucks.