To be honest, bro, like, if your girl couldn't stay loyal to you, especially if she's with your closest friend, you know, I mean, you can forgive her, but you can't be with her. That's one thing. You can forgive, but you can't be with her. Or something like, you can't forgive, but you can't forget. Yeah, forgive her, but move on. That's my advice for you.
No, because out of all the people she had to cheat on you with, it was your best friend. Like, out of a billion people on this earth, your best friend. The one right next to you. You act like she not gonna do it. Next is gonna be your brother.
Once a cheater, always a cheater. And if your ex actually gave a shit about you, she would have never cheated on you, no matter what. No, never forgive or forget.