Is it immoral to date your friends ex partner?

You can change the context to make it ok. Years after the breakup? Amicable breakup, not that close of a friendship, not serious dating just a casual hookup, with permission from the friend, etc.

I am trying to understand what you think the boundaries are, where it stops being moral.

Also those of you who think is immoral, why is it immoral? What harm is caused due to this act?

I can provide some ideas.

1) your friend doesn’t want that girl in his life anymore, he has moved on and he will see her, think of her through you. It will remind him of sad painful memories, hurt his current or potential relationships. (won't staying friends with your friend's ex also do this?) 2) he actually doesn’t want her to be happy, lots of exes stalk each other’s social media and verifying they didn’t do better. Does he really want her to find happiness? 3) We need this rule so that guys can introduce their gf to their friends without worrying about losing her to him. He can develop trust issues that his gf will leave him for his current friends. It’s not a stable secure relationship pattern when competition is allowed. I elaborated here 4) it’s a primal, irrational disgust or anger based on paternal uncertainty and slut behaviour. Something to do with the hindbrain, we evolved aversion to this behvaiour on a raw biological level. In some sense in his head he still sees her as a “partner” and no “friend” would put his dick in her. It’s incompatible categories. There is no rational logical reason but the emotions are still strong and valid. 5) if it’s a bad breakup, your friend feels like you didn’t believe his side of the story if you date her. You don’t trust his view that she is toxic. He might be worried for you. Choosing to date her reflects poorly on you, and he loses respect for you. Respect and trust are crucial for any friendship. 6) you can’t start a fresh relationship with her, you will have baggage of friendship, her past and all this drama makes it harder for the relationship to work.

Finally do you think you can trust your friend if he says it’s ok? It’s likely a friend would want to be the bigger man and try to be ok with it. So even if he says it’s fine, it’s possible he is not fine with it.

I think this topic matters a lot because a lot of people you are friends with, you share their values, interests, tastes and it’s likely you end up falling for someone in that circle. So it matters why we have this bro code in place. Like we need to understand it clearly so that we know when and where it is ok to bend the rules a bit.

If you think a hookup is also wrong then it’s likely 3 or 4 that is the true reason and we are just trying to rationalise a primal emotion.

Edit: new points, one of my few posts where I am actually learning from some comments. Thanks y’all.

7) he has told secrets to his ex which he doesn’t want his friends knowing. He wants to tell stuff to his friend which he doesn’t want his ex knowing. In the past he spoke to you, opened up and was vulnurable, expecting you had no conflict of interest, now he wonders since when you had these feelings for her. It feels like a betrayal since he may not have vented had he known.

8) when your ex dates a stranger you don’t know him and you can avoid comparison. If your ex dates a friend, you know your ex, yourself and the friend to such a level of detail that you end up comparing yourself to your friend in many ways. Does he make her happier than I did? Is he better than me? Is she treating him better than she treated me? Why is their relationship working and not mine? Wounds reopen, closure is lost.

”Comparison is the thief of joy.” – Theodore Roosevelt