Do you think it's right for your friend to become friends with your ex?

yes

even if this ex did you wrong?

It would depend on your relationship with the ex. My wife is still friends with her first husband, and that allows me to be. My friends, who are on bad terms with an ex, would not appreciate it if I warmed up to them. Thats basic.

No. It’s not fair. But then, life isn’t fair.

Thanks, everyone

My basic answer was to mock your basic question.

Fill in the damn details if you want help.

Not nice.

Define “friends” and “did you wrong”.
If you mean date, and she cheated on you, then no, it’s not a good thing.
If you mean he’s polite to her when he sees her, and she talked with/friended an ex-boyfriend on FB, then there’s nothing wrong with either of those things.

No they are friends like hanging out at each others house and posting pics of each other on facebook. and It’s two of my exes actually that he is friends with, one of my exes was years ago and I don’t care about but this other one was just a few months ago which lead me on, used me and a bunch of other shit and my friend knew this he was there for me. and he lied to me until I found the pics on facebook he said he didn’t even know my ex.

He must think the will have better luck with her than you. It’s probably time to give that relationship a rest, and cultivate other friendships that aren’t frustrating.

Oh I done nipped it in the bud I was just wonderfing If I was being childish

It depends. If they were friends before the split, then absolutely. If not, then it depends on how wrong – it’s not like most splits are amicable, so almost everyone feels “done wrong”. However, there are certain things – like was abusive – where it definitely wouldn’t be.

they didn’t even know each other

Did you ever stop to think that maybe they had something going on, in the past behind your back?

Their life, not mine.